In the 1965 Chicago College All-Star Game, which annually pitted the reigning NFL champion against star college players, Warfield shattered his collarbone and missed the majority of the 1965 season as a result. He returned for the penultimate game of the season and caught three passes for 30 yards before bruising his collarbone, causing him to miss the final game of the regular season. The Browns returned to the NFL Championship Game in 1965, in which Warfield caught two passes for 30 yards in a 23–12 loss to the Green Bay Packers.