The Chiefs acquired Downs and a 2027 seventh-round pick from the Colts on Tuesday in exchange for 2027 fourth- and fifth-round picks, Tom Pelissero of Netflix reports.
Mendoza will take over as the Raiders' new starting quarterback beginning with Sunday's game versus the Seahawks after Las Vegas traded Kirk Cousins to Minnesota on Tuesday, Adam Schefter of ESPN reports.
Chiefs coach Andy Reid said Monday that Mahomes (elbow) is considered day-to-day as this Sunday's game against the Falcons approaches, Sam McDowell of The Kansas City Star reports.