Already dealing with injuries to two of their top offensive players, the Indianapolis Colts were dealt another blow Wednesday as wide receiver Michael Pittman Jr. is expected to miss multiple weeks with a back injury, according to multiple reports.

Pittman was likely injured during the Colts’ 37-34 loss at the Jacksonville Jaguars last Sunday, though he played the entire game. It is unclear whether Pittman will land on injured reserve, which would force him to miss at least four games.

The fifth-year veteran has led the Colts (2-3) in receptions, receiving yards and receiving touchdowns in each of the last three seasons. He has a team-leading 22 catches for 238 yards and a touchdown through five games this year after signing a three-year, $70 million extension in March.

Pittman joins quarterback Anthony Richardson (oblique) and running back Jonathan Taylor (ankle) as key offensive weapons battling injuries. Both Richardson and Taylor sat out Sunday’s game in Jacksonville after getting hurt in Indianapolis’ 27-24 Week 4 win over the visiting Pittsburgh Steelers.

Richardson was limited in his return to practice Wednesday ahead of Sunday’s Week 6 game at the Tennessee Titans (1-3). Taylor and Pittman did not practice Wednesday, nor did receiver Josh Downs (toe). Alec Pierce has 13 receptions in five games for a team-high 368 yards with a 33.5-yard average.

Pittman, 27, has 358 career receptions for 3,900 yards and 16 touchdowns.