The Indianapolis Colts might be without Michael Pittman Jr. for a while.

The wideout is expected to miss multiple weeks with a back injury and is a candidate for injured reserve, according to ESPN’s Adam Schefter. An injured reserve stint would keep Pittman out for at least four weeks.

Pittman played in last week’s game against the Jacksonville Jaguars, catching five of eight targets for 37 yards and his first touchdown of the season. His injury popped up earlier Wednesday when he was a new addition to the Colts injury report, missing practice with the back injury.

Pittman leads Colts receivers in snaps, targets and receptions and ranks second behind Alec Pierce in receiving yards this season. He’s coming off a second career 1,000-yard season.

That’s a significant loss for a Colts offense that was already dealing with issues. Star running back Jonathan Taylor (ankle) and wide receiver Josh Downs (toe) were also non-participants in practice Wednesday, while quarterback Anthony Richardson was limited with an oblique injury,

The Colts are scheduled to play the Tennessee Titans on Sunday (1 p.m. ET, CBS) in Nashville.