Texas Rangers injured starting pitcher Jack Leiter was supposed to pitch two innings in his most recent rehab assignment but only pitched one inning. Now we have a better idea why.

Rangers manager Skip Schumacher told reporters in Milwaukee on Friday, including MLB.com, that Leiter was pulled from his relief appearance after one inning because he was experiencing an issue with his bicep.

The Rangers have shut him down for the next couple of days to see how his arm responds and then they'll make decisions from there, said Schumacher. It's the latest hiccup in a rehab that the Rangers had hoped would lead Leiter back to the Majors by the end of this month. Now, the path ahead is even murkier.

What’s Next for Jack Leiter?

To get Leiter back to the Majors soon, the Rangers talked about him rejoining the staff as a reliever. That’s why he entered Wednesday’s game with Triple-A Round Rock in the fourth inning. It was an attempt to see if Leiter could give Texas something in a relief role.

It didn’t go as hope. He gave up three hits and three runs in his one inning before he was pulled. In the moment, it seemed he might not be prepared to be a reliever. Now everyone knows there was something more to it — and the Rangers don’t have their answer about how Leiter can handle a relief role. Plus, there is the biceps issue.

Leiter went on the injured list in June after he had ankle surgery to remove an extraneous bone. Early on, he showed encouraging signs he might not need as much time to return to the Majors. Because it was an ankle injury that didn’t require a repair, he was able to continue throwing. He was already close to 40 pitches before he began his rehab assignment.

But in two games he experienced some mid-game fatigue and a loss in velocity that concerned the Rangers enough to attempt to move him into relief — at least in the short term.

Cal Quantrill has taken Leiter’s role in the rotation and give Texas great performances of late. Texas has also gotten a boost from left-hander Cody Bradford, though he has yet to win a game since he returned to the rotation earlier this month. But he was effective enough to move Jordan Montgomery to the bullpen when he returned from Tommy John rehab.

Right-hander Nathan Eovaldi is also on the injury list with an elbow injury. It's not clear when he'll return and he has not begun any significant rehab activities.

For now, the Rangers are trying to determine what to do next with Leiter. It will be a few days before they have a better read. But time is running out Leiter returning to the staff in any capacity with less than 30 games remaining in the season.