Kansas City confirmed the agreement Monday.
On Sunday, Terez Paylor of Yahoo Sports reported the Los Angeles Chargers offered a similar pact. However, McCoy signed with Kansas City because of his history with Chiefs head coach Andy Reid and the team's front office. Reid coached McCoy in Philadelphia from 2009 to 2012.
The 31-year-old rushed 161 times for 514 yards (3.2-yard-per-carry average) and three touchdowns for the Buffalo Bills last season. He also caught 34 passes for 238 yards. The veteran's 752 scrimmage yards and three touchdowns were the lowest marks of his career.
The ex-Bills back isn't far removed from an excellent two-year stretch when he had 3,209 scrimmage yards and 22 touchdowns in 2016-2017. However, McCoy took a step back in 2018 in his 10th NFL campaign, although some circumstances were out of his control.
Of note, he suffered a concussion, a hamstring strain and a rib fracture. He only missed two games, but the injuries may have slowed him during a season in which the Bills offense scored the second-fewest points per game in the league.
Buffalo's offense went through a rough stretch, with talented but developing rookie quarterback Josh Allen completing just 52.8 percent of his passes and the offensive line finishing 30th in adjusted line yards, according to Football Outsiders. Buffalo also cut struggling starting wideout Kelvin Benjamin in December.
Ultimately, McCoy's decreased production may have been the result of his age, injuries and the deteriorating offense around him. It's possible a change of scenery in Kansas City will revive a career in its latter stages.
The question is how the carries will be divvied up between Williams and McCoy. Williams shined when given the opportunity last year, gaining 5.1 yards per carry and catching 23 passes for 160 yards.
It's unclear how Williams will do as a team's lead back over an entire season, however, as he took over for the released Kareem Hunt late in the year.
At the very least, McCoy should get his fair share of touches as a backup to Williams. Mike Clay of ESPN provided his early projections, with Darwin Thompson also getting some looks:
The Chiefs open the season on Sunday, Sept. 8 against the Jacksonville Jaguars on the road.