MILWAUKEE — Right from the start, Kyle Hendricks just didn’t feel right.

As soon as he threw his first warmup pitch before the bottom of the first inning against the Brewers on Tuesday, Hendricks felt some pain in his right shoulder. That never went away, and as can be seen from the drop in his average velocities across the board, he was starting to labor through the innings when manager David Ross went out for a chat on the mound in the bottom of the second.

Generally, those initial mound visits feature pitching coach Tommy Hottovy strolling out to the mound, so seeing Ross going out there himself indicated it was for more than just getting Hendricks to settle down after he allowed a couple of baserunners.

“I just wanted some honesty,” Ross said. “I try to cut out the middleman sometimes. Just makes it a little easier to look somebody in the eye and hear their words, hear the tone of their voice. I felt pretty confident. He’s very honest with me. We have that kind of relationship, and so I trusted in that.”

Hendricks told Ross he could give him more, and Ross left him in to finish out the second and then to pitch a clean third. After that inning, however, Ross made the decision to take out Hendricks in favor of Matt Swarmer.

“I know he was grinding,” Ross said. “He wasn’t feeling great. He tried to push through, and it just didn’t look good. My gut (feeling) was to take him out.”

“Rossy knows me, so he knew,” Hendricks said. “He could see it, and there was no point in pushing it. It’s not something that’s so bad that it’s going to get out of control, but just not great. Something we definitely got to get checked out and just see what it’s all about.”

The Cubs announced that Hendricks was removed from the game due to right shoulder soreness. Hendricks said everything leading up to the game went smoothly, but it wasn’t until that first warmup pitch that the discomfort started, and though he wanted to pitch through it — “It’s not going to blow up on you or anything,” he said — he realizes that Ross’ decision to go to the ‘pen was probably the smart move.

It was a frustrating exit for Hendricks, especially considering it’s similar to an ailment he was dealing with at this time a month ago. After a start on June 1, Hendricks didn’t pitch for 13 days due to a similar shoulder issue. The Cubs allowed him some extra rest to take care of it, and he managed to find a little more consistency in the three starts afterward (1-1, 3.78 ERA, 18 strikeouts, 2 walks), including 7 1/3 innings of shutout baseball in his last start in St. Louis.

But that run ended after just three innings in Milwaukee. Hendricks said he was a little encouraged because the similarity in the feeling meant he has an idea of what the issue is, though that doesn’t lessen the frustration of another short start in a season full of them for the Cubs.

Neither Ross nor Hendricks had an update on how much time Hendricks could miss. Hendricks noted he expects to get an MRI on his shoulder and then the group will assess the situation from there, but he said the possibility that he could miss his next turn through the rotation “might be a good conclusion to pull from this.”

“It’s just super frustrating that (I was) feeling really good coming into this, doing everything good, my volume has been down,” he said. “I just don’t know where it came from.”

Adding to Hendricks’ (and the Cubs’) frustrations is the fact that he could be just the latest rotation arm to hit the shelf.

As of Tuesday night, Justin Steele was the lone healthy starter who had a shot to be in the rotation on Opening Day. Taking Hendricks’ injury into account, the Cubs also have Marcus Stroman (right shoulder inflammation), Drew Smyly (right oblique strain), Wade Miley (left shoulder strain) and Alec Mills (low back strain) still on the 15-day injured list.

Both Miley and Mills started the season on the IL. Miley dealt with left elbow inflammation that forced him to miss the first month, and he’s since had two separate stints on the IL with left shoulder strains. Mills missed the first two months after he was transferred to the 60-day IL, then lasted just seven outings (two starts) before leaving his start Saturday after just seven pitches.

Stroman and Smyly’s returns both appear to be close. Stroman made his first rehab start with Triple-A Iowa on Sunday and Smyly with High-A South Bend on Monday, and both were back with the Cubs in Milwaukee on Tuesday. However, Ross said pregame that no full plan was set and he still had to meet with both to map out next steps.

Which means for now, Hendricks and Steele remain the only preseason starting options not currently on the IL — and the Cubs may be down to just Steele once they get back Hendricks’ test results.

​”Of course. That adds to it,” Hendricks said about the frustration knowing that he could be the next starter to go down with an injury. “But just in general, I want to be out there every fifth day. That’s what I get paid to do, obviously, and just to be here for this team and be the best I can be. I was starting to feel good, just getting some consistency, so that’s really frustrating on that end.”

If that’s the case, and if Stroman and Smyly aren’t yet ready to return during this next turn through the rotation, Ross will have to get creative.

The Cubs have already had 13 different pitchers start a game for them this season. Keegan Thompson (who started Sunday against the Red Sox) and Adrian Sampson (who starts Wednesday’s series finale in Milwaukee) have joined the rotation after injuries piled up. Thompson will likely start Friday and Steele likely Saturday against the Dodgers, which means Thursday could feature a start from Mark Leiter Jr. or a bullpen day.

The Cubs have to be hoping Stroman or Smyly are ready to go by next week, though an off day Monday and the All-Star break the week after give them ways to shuffle around their starters.

But the shuffling is only necessary because of all the hits the rotation has taken this season, and Hendricks’ early exit might just be the latest to hit the club.