CHICAGO -- Cubs starter Marcus Stroman said there wasn’t one specific thing that led to his hip ailment. But there was a point when the right-hander knew it was time to address the lingering issue.

“When I felt like I had zero lower half,” Stroman said Wednesday. “I felt like in the first inning last game [Monday], I felt like I was in inning eight or nine.”

The Cubs placed Stroman on the 15-day injured list on Wednesday with right hip inflammation, a move retroactive to Tuesday. In a corresponding move, they added newly acquired reliever Jose Cuas to the active roster.

Stroman said he’s been feeling the hip issue “for a bit now.” As the ailment lingered, it gradually got worse and started affecting his mechanics on the mound to the point where he couldn’t fire his glute or quad, and he started compensating with his upper body.

“I've been trying to change mechanics and do a lot of things, honestly, to get around it,” Stroman said. “It’s just at the point where I couldn't do too much more to change and feel like I wasn't throwing at like 140, 150 percent out there.

“I felt like I had to do so much, essentially just throwing all upper body and arms," added Stroman. "I think it was at a point where taking a break and getting in the weight room and doing what I need to do, I feel like, is just going to springboard me and put me where I was -- and where I need to be.”

Stroman had a dominant run to start the season that earned him his second career All-Star nod and consideration to start the Midsummer Classic. He had a 2.47 ERA in 17 starts through June.

Stroman didn’t specify exactly when his hip started bothering him, but he’s been in a rough patch the last month. Since July, he has a 9.11 ERA in six starts (27 earned runs in 26 2/3 innings) and has thrown one quality start in that stretch. He had 14 this season entering July, and acknowledged the frustration in not being able to overcome the issue and get results in the weeks since.

“Oh, beyond frustrating,” he said. “I do so much in between starts to get right and to focus on things. When everything you're doing is not fixing it, like I said, I feel like I just had to go to the root of the problem rather than trying to get around it.

“I'm not even slightly worried. I know after this, I'm going to feel strong. I’m going to get on a program with the trainers and I should be right [back] to where I was.”

Stroman, who’s eligible to come off the IL on Aug 16, said the plan right now is for him to only miss one start. He received a cortisone shot on Wednesday and is slated to begin a strength and stability program in the next few days.

The Cubs have three off-days between now and Aug. 16, so they have flexibility to adjust their rotation in the meantime.

“When I come back for my start,” Stroman said, “I feel like I should feel really strong and stable, right where I need to be.”