SARASOTA, FLA. — Orioles right-hander Chris Tillman was forced to abandoned a plan to throw what was seen as a pivotal bullpen session Sunday after shoulder discomfort cropped up just 10 warmup throws into a game of catch.

His deliberate path toward an early-April return appears to have taken a wrong turn, and the Orioles will almost certainly be without him for the beginning of the season — if not for much longer.

The recurring shoulder soreness, which manager Buck Showalter said is the same problem that cost Tillman three weeks last August, re-emerged when the star right-hander began his throwing program in December.

“We think we’ve got a pretty good feel for what the issue is, structurally,” Showalter said. “I’m still very confident he’ll pitch for us at some point this year. We’ll see what the next few days bring. Just the start of the season is in jeopardy — doubtful. That’s a better word than ‘jeopardy.’?”

Tillman, an All Star in 2013, has started 30 or more games in each of the past four seasons. Last year, he went 16-6 with a 3.77 ERA. It was the third time in four years he finished with an ERA below 3.80.

When the injury sidelined Tillman last year, he described it as right shoulder bursitis, which is inflammation of the fluid sack in the shoulder joint. Tillman described it at the time as mostly discomfort between his outings, not while he was throwing.

He rested for three weeks before returning for the stretch run, and hoped a few months off in October and November would eliminate the problem entirely. He got a platelet-rich plasma injection in December in hopes of speeding up the recovery.

That meant Tillman came into camp on a rehabilitation track. Only in the last few weeks did he begin to ramp up his throwing activities. Still, it was clear from the beginning of spring training that he would not make a fourth straight Opening Day start.

He has already had two bullpen sessions — the first going better than the second — and a third was scheduled for Saturday but pushed back to Sunday. Showalter said Tillman was “not feeling completely normal” during and after the second bullpen session, and the team changed antibiotics he was taking to alleviate the possible side effect of joint soreness that could come with it.

Today’s aborted session shows it could be more than the medicine.

“Started to play catch, long-toss to start to get ready to go to the mound, and after about 10 throws they shut it down,” Showalter said. “He’s still got some discomfort there.”

With head athletic trainer Richie Bancells in Fort Myers with the club for a day game against the Minnesota Twins, Showalter said Dr. Leigh Ann Curl, the Ravens’ team surgeon and the Orioles’ assistant physician, was at the team facility in Sarasota checking out Tillman’s shoulder. Curl was already in town and did not come specifically to see Tillman.

“They’ll get their heads together,” Showalter said before Sunday’s game in Fort Myers, Fla. “We’ll see. I’d like to think that medication had something to do with it, but it’s just kind of the same spot. We’ll see.”

However, Showalter said a few hours later that there wasn’t much conversation between Tillman and the medical staff during the day — only when he relayed his problem on the field.

“They didn’t really spend a lot of time talking to Chris, other than on the field,” Showalter said. “After, they kind of convened about what the next move might be if it continues down this path.”

If the medical staff decides Tillman needs another opinion, a lot more than just the start of the season could be in jeopardy for Tillman, who is one year from free agency.

“It’s the same thing he missed time with last year,” Showalter said. “He could start back from scratch. We think we know what we’re dealing with physically. If that is still the same, there hasn’t been some change in that, he should be able to pitch at some point — just not quite as quick as we had hoped. The worst-case scenario for me — well, not worst — but he kind of starts over from scratch and stays down here in extended spring. It looks like he’s got a chance to be left here with [minor league medical coordinator] Dave Walker, but I’m hoping something changes in the next week. He may try it again, I don’t know, or we may get back and he’s headed for a second opinion. This is a big year for him.”

Before this, the hope for Tillman was he’d continue to rest and rehab his shoulder for the first few weeks of spring training before escalating to a game Friday. That would have put him in line to maybe miss the first week or so of the regular season.

The Orioles don’t need a fifth starter until April 15 (Tillman’s 29th birthday), so the rotation could be manipulated. But now attention turns to who might be able to open the season in Tillman’s spot in the rotation.

Right-handers Mike Wright and Tyler Wilson are in the equation, though impressive springs from left-handers Chris Lee and Jayson Aquino have elevated each of their stocks in Showalter’s eyes. Right-hander Gabriel Ynoa, who was acquired last month from the New York Mets, is also in that mix.

If they go the outside route, free agent starters still on the market include Doug Fister, Colby Lewis and Edwin Jackson.

jmeoli@baltsun.com

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