The Kansas City Chiefs are signing Joe Thuney on a five-year, $80million deal, giving Patrick Mahomes some help on the offensive line.

ESPN's Adam Schefter reported on Monday, the first day of negotiating with free agents, the Chiefs were signing the sixth-year guard.

Thuney spent his first five seasons in the NFL with the New England Patriots, winning two Super Bowls.

The 28-year-old played all 90 regular season and playoff games during his time in New England and became the first player to start three Super Bowls in his first three years in the league.

Thuney has allowed just 1.5 sacks over the past three campaigns, continuing to protect Cam Newton - Tom Brady's replacement - last year when playing on the franchise tag.

That protection will be welcomed in Kansas City, where the Chiefs are attempting to build another challenge after seeing their title defence ended by Brady's Tampa Bay Buccaneers in the big game.

Mahomes has established himself as the NFL's best quarterback but was exposed by the Bucs.

The Kansas City superstar was sacked three times and failed to throw a touchdown as he went 26-for-49 for two interceptions and a 52.3 passer rating.

Shaq Barrett, another of Monday's big free agent signings, returning to Tampa, had 13 pressures against Mahomes.