The veteran running back, 35, was surprisingly cut by Washington earlier this week but has quickly found a new home ahead of the 2020 NFL season, which begins next week.
Peterson confirmed he was travelling to Detroit to sign for the Lions in a text to reporter Josina Anderson.
"They're giving me an opportunity to play," he said.
"I know coach [Darrell] Bevell from my days in Minnesota. Ultimately I feel comfortable going there and helping them to get better."
Bevell is the offensive coordinator in Detroit and held that role for five seasons with NFC North rivals the Minnesota Vikings – where Peterson enjoyed the best years of his career – between 2006 and 2010.
Peterson, drafted by the Vikings in the first round of the 2007 NFL Draft, was a 1,000-yard rusher in each of his four seasons working with Bevell in Minnesota and he led the league in rushing yardage in 2008 when he amassed 1,760 yards.
Since leaving Minnesota after the 2016 campaign, Peterson has played for the New Orleans Saints, Arizona Cardinals and Washington – for whom he accrued 1,940 rushing yards across two seasons.
He will enter his 14th year in the league hoping to add to 14,216 career rushing yards, which are the fifth-most of all time.
Detroit legend Barry Sanders is fourth of the list with 15,269.
The Lions had already drafted running back D'Andre Swift in the second round of the 2020 NFL Draft and he is expected to compete for starting snaps with Kerryon Johnson, another second-round pick who has struggled to stay healthy since entering the league in 2018.
Detroit begin their 2020 season against the Chicago Bears at Ford Field next Sunday.
There have been nationwide protests in the United States after Floyd – an African-American man – died in police custody in Minneapolis on May 25.
A police officer was filmed kneeling on Floyd's neck during an arrest after he was crying out for help as he was handcuffed and pinned to the ground.
Former San Francisco 49ers quarterback Colin Kaepernick was the first player to kneel during the anthem in protest against racial injustice in 2016, before he was released the following year.
New Orleans Saints star Drew Brees said players who knelt during the anthem were "disrespecting the flag", comments which sparked fierce backlash and led to an apology.
Peterson – a former team-mate of Brees in New Orleans – weighed in and the 35-year-old told the Houston Chronicle: "Just four years ago, you're seeing [Colin] Kaepernick taking a knee, and now we're all getting ready to take a knee together going into this season, without a doubt."
"Yeah, without a doubt, without a doubt," 2012 NFL MVP Peterson replied when asked if he personally planned to take a knee.
"We've got to put the effort in as a group collectively. Are they going to try to punish us all? If not, playing football is going to help us save lives and change things, then that's what it needs to be."
Redskins veteran and seven-time Pro Bowler Peterson, who moved to Washington from the Arizona Cardinals in 2018, ran for 898 yards and five touchdowns last season.
Baltimore went for the two-point conversion and the win after the Ravens scored a touchdown with 12 seconds remaining on Sunday, but Jackson's pass went agonisingly off Mark Andrews' fingertips with the endzone in sight.
The Steelers prevailed in another thrilling AFC North battle to snap a two-game skid after Roethlisberger (21-of-31 passing for 236 yards and two TDs) threw two fourth-down touchdowns to fuel Pittsburgh.
After a scoreless opening period, Devonta Freeman rushed for a TD as the Ravens (8-4) took a 10-3 lead into the final quarter away to the Steelers (6-5-1).
The fourth period came to life, veteran quarterback Roethlisberger started the comeback with an early 29-yard touchdown pass to Diontae Johnson before the pair combined against less than two minutes from the end.
Trailing 20-13, former MVP Jackson (23-of-37 passing for 253 yards and a touchdown) led an eight-play, 60-yard drive for his only touchdown of the game but Baltimore were unable to complete the two-point conversion at the death.
Since the 2016 season, six of Pittsburgh's seven wins against Baltimore have come by seven points or less, per Stats Perform.
Seahawks snap skid by sinking Niners
The Seattle Seahawks needed a victory and they got it after powering past the San Francisco 49ers 30-23.
In a mistake-filled contest, the Seahawks ended their run of three consecutive losses behind Russell Wilson's two-touchdown display in Seattle.
Future Hall of Famer Adrian Peterson made his debut for the Seahawks and scored his 126th career touchdown on a one-yard rush. It broke a tie with Hall of Famer Walter Payton and moved the 36-year-old into a tie with Jim Brown for 10th in NFL history.
Jimmy Garoppolo threw two interceptions for the beaten 49ers.
The Los Angeles Rams also snapped a three-game skid, rolling over the Jacksonville Jaguars 37-7 after Odell Beckham Jr., Cooper Kupp and Van Jefferson all caught TD passes from Matthew Stafford.
Hounded throughout the game by the Tennessee Titans' defence, Stafford threw two critical interceptions as the Rams fell 28-16 at home.
The turning point of the game occurred early in the second quarter, when Stafford tried to throw the ball away while being pulled down by Jeffrey Simmons in the end zone.
His blind heave landed in the arms of Titans linebacker David Long, who returned it to the two-yard line and set up a Tennessee touchdown on the next play.
The Rams (7-2) got the ball back after the kick-off and Stafford took to the air again, trying to hit Robert Woods, but Titans defensive back Kevin Byard jumped it and went 24 yards for the Titans' second TD in 11 seconds.
It was the 24th time Stafford had an interception returned for a touchdown, the most of any active NFL quarterback.
"I mean, I basically spotted them 14 points," Stafford told reporters. "Can't do that in the NFL, especially against a good team like that that wants to get out in front, run the football, mix coverages, do all that kind of stuff. Just wasn't good enough early in the game.
"Turnovers really killed us and those are on me, so if I clean those up and I know I will, I've got a lot of confidence in this team to go out there and play some really good football."
Though Stafford could have made better decisions on both of those plays, Tennessee's defenders were flying around the field all game.
The Rams had surrendered an NFL-low eight sacks through the first eight games, but the Titans (7-2) brought down Stafford five times on Sunday.
"Those guys played fantastic," Titans head coach Mike Vrabel said of his defence. "It was fun to watch them play.
"We really think that group is playing with a lot of confidence right now. They would be able to come in here and play the way they did and hold them to field goals, and we played great in red zone."
Tennessee twice forced the Rams to settle for field goals in the red zone and did not surrender a touchdown until Stafford threw a three-yard pass to Sony Michel with 24 seconds to play in the game.
It all added up to a winning formula for the Titans even as they managed just 194 yards of total offence while playing without their injured star Derrick Henry.
"Those guys played some great ball defensively. It made up for our lack of offence," said veteran running back Adrian Peterson, who signed with Tennessee this week and scored his 125th career touchdown.
"You hear all this talk about the Rams' defence. What about the Titans' defence? Those guys came out and played outstanding."
Struggling Seattle had signed future NFL Hall of Famer Peterson earlier this week but elevated the 36-year-old on Saturday, despite only two days of practice.
The Seahawks (3-8) brought in the 2012 MVP and seven-time Pro Bowler – who was waived by the Tennessee Titans – for depth due to a growing injury list.
"Adrian had a good week," Seahawks head coach Pete Carroll said on Friday, with his team amid a three-game losing streak. "It's probably hard for people on the outside to understand the impact a guy with his kind of background can make.
"At a time where we're battling to try to win a game and get going, he jumped in here and had a remarkable influence on the week. With three guys banged up at the spot, we'll see how it goes on the weekend. He had a really productive week for us, and it was fun having him here.
"It's a rare opportunity for our guys to see somebody like that, that has that kind of background, but stands for so much more than just the numbers and the stats and all of that.
"He's been a remarkable competitor forever. It was so obvious. It was really a boost for a bunch of guys, the young guys in particular. He's serious about playing. He's not just here for show. He's here to come here and try to help us win a game."
The Seahawks have lost eight or more games in a season for the first time since going 7-9 in 2011. The nine straight seasons with seven of fewer losses is the longest streak in team history with the previous record being five straight seasons (2003-2007), according to Stats Perform.
Russell Wilson led the Seahawks in rushing with 16 yards in their 17-15 loss to the Washington Football Team. It was the lowest number of rushing yards for the team's leading rusher since Week 9 of 2016 when Tyler Lockett led the way with 13 rushing yards against the Bills.
Rams quarterback Matthew Stafford threw two interceptions in a 26-second span early in the second quarter, leading to a pair of rapid-fire Titans touchdowns.
The first was an ill-advised attempt to throw the ball away while being dragged down in the end zone that David Long intercepted at the Rams' eight-yard line.
After Geoff Swaim scored on a two-yard TD pass from Titans QB Ryan Tannehill on the ensuing play, Stafford's next pass was picked off and returned 24 yards for a TD by Kevin Byard.
Tannehill would run the ball in for another score prior to half-time as the Titans built a 21-3 lead before handing the game over to their ferocious defence, which sacked Stafford five times after LA entered the game with only eight sacks allowed all season.
Titans recruit Adrian Peterson scored his 125th career TD, joining 11 other players to score 125-plus career touchdowns.
The Rams (7-2) would not find the end zone until Stafford hit Sony Michel for a short TD with 24 seconds remaining in the game as they fell behind the victorious Arizona Cardinals (8-1) in the division race.
Tennessee (7-2) now hold the best record in the AFC despite being out-gained 347-194 as star running back Derrick Henry remains sidelined with a foot injury.
Tannehill completed 19 of 27 passes for just 143 yards with a TD and an interception but his 79.7 passer rating was still better than Stafford's 71.0 after the Rams QB finished 31-of-48 passing for 294 yards.
Peterson was signed to the Titans' 53-man roster earlier this month after star running back Derrick Henry's season-ending foot injury.
However, the Titans waived the 36-year-old and 2012 NFL MVP after only three games.
Peterson debuted for the Titans in the 28-16 win over the Los Angeles Rams in Week 9 – he scored with a one-yard touchdown.
The veteran rushed for 82 yards across 27 carries as well as four receptions for eight yards in his three games for the Titans, who are 8-3 for the season and top of the AFC South.
The decision on Peterson was one of 13 roster moves made by the Titans on Tuesday, including adding defensive back Buster Skrine, running back Dontrell Hilliard and outside linebacker John Simo to their active roster.
Quarterback Tom Brady was one of eight players unanimously voted to the team.
Brady topped all quarterbacks during the decade with 138 wins, including the playoffs, and led the New England Patriots to Super Bowl titles in 2014, 2016 and 2018.
Aaron Rodgers was the other quarterback on the team, beating out NFL career passing leader Drew Brees.
Rodgers won the Super Bowl with the Green Bay Packers in 2010 and posted 106 victories, including the postseason, to finish second behind Brady in wins.
Brees' 99 combined victories with the New Orleans Saints were the third most in the NFL.
Running back Adrian Peterson, offensive linemen Joe Thomas and Marshal Yanda, defensive linemen J.J. Watt and Aaron Donald, linebacker Von Miller and kicker Justin Tucker were also unanimous selections.
Darren Sproles became the fourth player ever to be named to an All-Decade Team at multiple positions as he was selected as a punt returner and an offensive flex player.
New England's Bill Belichick and Pete Carroll of the Seattle Seahawks were the two coaches selected, with Belichick joining former Pittsburgh Steelers coach Chuck Noll as the only coaches to be on two All-Decade Teams.
Belichick led the Patriots to the playoffs in each season during the decade and won three Super Bowls with Brady as his quarterback.
Carroll coached the Seahawks to eight playoff appearances and a Super Bowl title in 2013.
The veteran running backs are due to face off in the squared circle at Los Angeles' Crypto.com Arena on July 30.
Bell, a three-time Pro Bowler, made the announcement on social media.
"[And] it's official nothing else needs to be said, let's gooo," Bell, 30, posted on Twitter, accompanied with a poster promoting the bout.
Peterson is not officially retired from the NFL but made just four appearances for the Tennessee Titans and Seattle Seahawks in the 2021 season.
The 37-year-old became a star name during a 10-year stint with the Minnesota Vikings and was named MVP in 2012 - a campaign where he became the seventh player to rush for 2,000 yards in a season.
Peterson ranks fifth on the NFL's career rushing yards list with 14,918 and is a seven-time Pro Bowler.
Like Peterson, Bell has not officially hung up the cleats but has struggled to find a permanent home since leaving the Pittsburgh Steelers in 2018. Last season, he made eight appearances for the Baltimore Ravens and Tampa Bay Buccaneers.
ESPN reported the fight will take place on the undercard of Social Gloves 2, an event promoted by YouTube star Austin McBroom.
Washington had until February 25 to exercise their club option, which ensures them of Peterson's services for next season on a $2.25million salary and keeps him out of free agency.
Peterson will carry a cap hit of $3.1m and his dead cap figure would have been just $750,000, but his importance to the Redskins was underlined by their move to keep him, which was announced on Wednesday.
A month ahead of his 35th birthday, Peterson has kickstarted his career with the Redskins, starting 31 of their 32 games in the last two seasons, rushing for 1,940 yards and 12 touchdowns.
The seven-time Pro Bowler has added 37 catches, 350 yards and a further score through the air and will remain with the rebuilding team, who have second-year pro Dwayne Haskins at quarterback.
Ron Rivera, the team's new head coach, hailed Peterson's professionalism as he sets about improving on a disappointing 3-13 season.
"Adrian Peterson is the epitome of what it means to be a pro in this league," said Rivera, whose team hold the second overall pick in the 2020 NFL Draft.
"Adrian's leadership and passion towards the game of football will set an example of what is expected of the players in this program moving forward."
Peterson enters his 13th NFL season fifth all-time in rushing yards with 14,216, a total which is 1,054 behind Barry Sanders, and fourth in career rushing touchdowns having scored 111.
Veteran running back Peterson - the 2012 MVP - looked set for a reduced role under new head coach Ron Rivera this year.
But the 35-year-old was cut on Friday as Washington aim to decrease the age profile of their roster in an offseason of change.
Rivera has replaced interim coach Bill Callahan, and Jason Wright has been installed as president, while the team is in the process of changing their name.
Peterson still did not anticipate his place was in question, though, telling ESPN: "It comes as a surprise. I didn't feel I showed anything that would warrant being released."
The seven-time Pro Bowler, who made his name in 10 seasons with the Minnesota Vikings, had been at Washington for two years, missing just one game in that time.
Peterson had 462 carries for 1,940 yards and 12 touchdowns, also scoring a single rare receiving TD.
Despite Friday's shock news and his advancing years, Peterson is confident he still has a future in the NFL.
"Without a doubt, I definitely want to play," he added. "We'll see what happens.
"Every new chapter is a blessing. Whatever comes next, I'll be blessed to attack it. I can't be down on myself. I know it wasn't because of my ability or inabilities to do something. It came down to those guys making their decision.
"It just sucks because I feel this team really has some promise and I won't be a part of it."
Washington start the year against the Philadelphia Eagles next Sunday.
