WESTFIELD, Ind. -- The Indianapolis Colts have another issue on their hands at running back.

Zack Moss, who was working with the starting offense in the absence of Jonathan Taylor, sustained a broken arm in Monday's practice and will miss roughly four to six weeks, a source confirmed to ESPN.

Moss took a hit during Monday's practice -- the first day in pads -- and immediately reacted, slamming his helmet and grabbing his right arm. Moss, who was traded to the Colts last season from the Buffalo Bills in a deal involving running back Nyheim Hines, is expected to be an important part of the Indianapolis running game with dual-threat quarterback Anthony Richardson in the backfield.

But Moss has had a bigger presence than expected given the status of Taylor, who remains on the physically unable to perform list and is at odds with the team over his lack of a contract extension.

A 2020 third-round pick from Utah, Moss rushed for 365 yards in eight games with the Colts last season. He's tallied 1,282 rushing yards and nine rushing touchdowns in his three seasons. While he's out of the lineup, look for third-year backup Deon Jackson and rookie Evan Hull to take the lead at running back for the Colts.

Moss' diagnosis was first reported by NFL Network.