MILWAUKEE -- An MRI revealed Marlins starter Sandy Alcantara has a right UCL sprain, manager Skip Schumaker said prior to Miami’s game vs. Milwaukee on Wednesday.

Alcantara was initially diagnosed with a right forearm flexor strain and he was placed on the 15-day injured list Sept. 6 after feeling discomfort during his Sept. 3 start.

He played catch for the first time since that outing on Wednesday.

“Obviously, anything with the elbow you're concerned about,” Schumaker said. “But he still feels like he can have a throwing progression, which he started today. We’re going to take it day by day.”

This is the first time Alcantara, who has a 4.14 ERA in 28 starts this season, has gone on the injured list in his career due to an arm issue.

He threw off flat ground Wednesday under the watchful eye of the Marlins training staff. In speaking with reporters afterward, the right-hander said his arm feels “100 percent good” right now.

His next steps are not immediately clear, and both Alcantara and Schumaker were non-committal regarding whether Alcantara will return this season. Both stressed they’re taking things day by day.

The Marlins have 16 games remaining, excluding Wednesday’s matchup with the Brewers. Tuesday is the first day Alcantara is eligible to come off the IL.

“I will say that watching him throw is always a good thing,” Schumaker said. “And again, it’s a progression. We're gonna watch it every day and go from there.”

Said Alcantara: “I don't know. I can't say yes. I can't say no. I’ve just gotta be positive. I just gotta keep telling myself day by day and try to take advantage of the opportunity.”