LaFell, who enters his fifth NFL season, played the last four with the Carolina Panthers. At 6-foot-2 and 210 pounds, he is an inside/outside receiver who started all 16 regular-season games in 2013 and finished with a career-high 49 catches for 627 yards and five touchdowns.
Against the Patriots in 2013, LaFell had a season-high seven catches for 59 yards and a touchdown in the Panthers' 24- 20 win in Week 11
LaFell entered the NFL as a third-round draft choice of the Panthers in 2010 after playing for LSU.
He is the second wide receiver the Patriots reached agreement with on Saturday. The team also brought back Julian Edelman.
Information from ESPN.com Patriots reporter Mike Reiss contributed to this report.