Mitchell has 21 days to practice before the Patriots must make a decision whether to activate him, but he is eligible to re-join the 53-player roster at anytime. Mitchell could help New England in the playoffs, even though the Patriots have receivers Brandin Cooks, Chris Hogan, Danny Amendola, Phillip Dorsett, Kenny Britt and special teams captain Matthew Slater.
Hogan has missed six of the past seven games with a shoulder injury, and Britt joined the team just two weeks ago.
Mitchell quickly became a favorite of quarterback Tom Brady‘s last season, catching 32 passes for 401 yards and four touchdowns as a rookie. He made six catches for 70 yards in Super Bowl LI, including five for 63 in the second half as the Patriots rallied against the Falcons.