The Dallas Cowboys and New Orleans Saints will each enter the 2020 season with high-profile backups.
Dallas signed Andy Dalton to a one-year, $7million contract on Saturday, the former Cincinnati Bengal following Jameis Winston in finding a new home.
Winston signed with the New Orleans Saints on a deal worth only $1.1m, a meagre sum for the NFL's passing yards leader in 2019.
They are excellent options to have in reserve and feature on our list of the best backups in the league.
Nick Mullens - San Francisco 49ers
Key Stat: Mullens' yards-per-attempt average of 8.31 ranked fifth in the NFL in 2018.
Mullens couldn't rescue San Francisco's 2018 season, which fell apart when Jimmy Garoppolo tore his ACL in Week 3. However, after he replaced an injured C.J. Beathard in Week 9 he kept the starting job for the rest of the campaign.
He impressed with his poise and his ability to run Kyle Shanahan's offense, keeping the Niners competitive down the stretch and winning three of his eight starts. Mullens was arguably the premier backup in the league going into the 2019 season but was not needed to step in as Garoppolo helped the 49ers to the Super Bowl.
Jacoby Brissett - Indianapolis Colts
Key Stat: Brissett was tied for 11th in touchdown-to-interception ratio in 2019, throwing for 18 scores and just six picks.
The starter for the Colts last season after Andrew Luck's shock retirement, Brissett looks set to return to the backup role for the last year of his contract.
Indianapolis signed Philip Rivers to a one-year deal in the offseason, with the Colts deciding to upgrade after Brissett failed to elevate a team that struggled with injuries to the playoffs last season.
Brissett, however, has an extremely strong arm, can make plays on the move and took care of the football in 2019. His 12-20 record as a starter should not discourage teams from trying to sign him next offseason or acquire him in a trade ahead of the 2020 campaign.
Marcus Mariota - Las Vegas Raiders
Key Stat: Mariota had his best statistical season in 2016, ranking in the top 10 in passer rating (95.6), TD-INT ratio (2.89) and yards per completion (12.41)
Mariota declined in 2019 and surrendered his starting role with the Tennessee Titans to Ryan Tannehill, who led them to the AFC Championship game.
The second overall pick in the 2015 draft, Mariota unquestionably has the right pedigree, having guided the Titans to a playoff win in the 2017 season.
He has the skill set as a thrower and a runner to push starter Derek Carr and it would be no surprise if the Raiders' first season in Las Vegas is marked by a quarterback controversy.
Andy Dalton - Dallas Cowboys
Key Stat: Dalton was second in the NFL with a passer rating of 106.3 in 2015, only Russell Wilson (110.1) was superior in that regard.
The Cowboys' decision to invest in another quarterback may raise eyebrows given they are still to sign starter Dak Prescott to a new deal.
However, the expectation is that Dallas will eventually get a deal done with their franchise quarterback, and Dalton gives them an insurance policy who is worthy of having a starting job.
Dalton played at an MVP level in 2015, when a broken thumb derailed his and the Bengals' Super Bowl aspirations. He never recaptured that form in Cincinnati but his availability to serve as a backup for the Cowboys is indicative of the surplus of quarterback talent in the league.
Jameis Winston - New Orleans Saints
Key Stat: Winston's 5,109 passing yards led the NFL in 2019, he racked up 54 passing plays of 25 yards or more.
Winston was once thought to be seeking a contract in the region of $30million a year as his time with the Tampa Bay Buccaneers neared its end.
However, his proclivity for turning the ball over - he threw 30 interceptions in 2019 - was undoubtedly a factor in him having to settle for a substantially less lucrative deal in New Orleans after the Bucs opted to sign Tom Brady.
The first overall pick in 2015, Winston carries considerable upside as a downfield passer and is the most talented reserve in the NFL.
He has yet to channel that talent into consistency but, with Drew Brees approaching perhaps the final season of his decorated career, Winston has the perfect opportunity to transform his fortunes under head coach Sean Payton.