SCOTTSDALE — Arizona Diamondbacks starting pitcher Zac Gallen is questionable for Opening Day due to a shoulder issue he sustained during the winter.

Manager Torey Lovullo told reporters on Monday that Gallen felt shoulder stiffness while going through his offseason throwing program. Gallen went for an MRI on his own due to MLB’s lockout, and he was diagnosed with bursitis, which is an inflammation of fluid-based sacs in a joint.

Lovullo said he did not know when the discomfort began, nor did he have an answer to whether Gallen will be ready by the start of the season.

“His progression might be a little slow right now,” Lovullo said. “We’ll find out in the coming days about how he’s feeling, but all indications are he’s feeling very, very good. It’s just his progression was delayed a little bit.”

Gallen was third on the D-backs in starts and innings pitched last season. He led the team in strikeouts per nine innings with 10.3 and he finished with a 4.30 ERA.

The 26-year-old is scheduled to throw a couple of bullpens this week starting on Tuesday. He was at camp on Monday.

Lovullo said Arizona’s medical staff has been in a crash course to get up to speed with each player’s status. Players could not communicate with their teams during the lockout, which threw a wrench into the way the D-backs operate.

“Typically, when we say goodbye to these players, the offseason is one that we are extremely hands on about,” Lovullo said. “This was such a unique situation where we were unable to gather information about where these guys were. We were getting secondhand news the best way that we could because, obviously, we care about our guys.”

Lovullo also gave updates regarding All-Star infielder/outfielder Ketel Marte, who did not participate on the field Monday.

Marte has an eye infection and is considered day-to-day. He told reporters that he thinks there was something on his finger while he inserted his contact lenses.

Follow @alexjweiner