Since then, Cooper has been absent from the team having recently flown to Chicago to meet with Cubs Orthopedist Dr. Stephen Gryzlo. Cooper received a cortisone shot and is now in Mesa, Ariz., at the Cubs' rehab facilities, where he expects to return to Daytona sooner rather than later.
"I'm actually feeling pretty good now," the right-hander said from Mesa on Saturday. "I had that shoulder tendonitis toward the end of last year and I think it just flared up again. I just had an MRI and there was no tear."
The initial word around Daytona was that Cooper had left the April 12 appearance with a hamstring-related injury, but that wasn't the case.
"It had nothing to do with my legs. I sort of wish it was a hamstring," Cooper said lightheartedly. "Those seem to heal quicker."
A 26th-round draft pick from California last season, Cooper went 2-0 with a 1.23 ERA in 22 innings from relief last season with Boise. He struck out 13, walked 11 and held opposing hitters to a .185 average against.
Cooper alternated between starting and relieving in college, but he seemed to find his niche in the closer's role last summer with nine saves. He turned 23 in the off-season and made the jump from short-season ball to Class High-A this spring.
The most frustrating thing about the recent setback was not so much the flare-up itself, Cooper says, but knowing that he wasn't pitching with his best stuff.
"It's a frustrating feeling," he said. "When you have your best stuff, you can always tip your hat to the hitter. Not when you're hurt (though)."
Cooper doesn't plan on waiting very long before he rejoins the Daytona club. The ETA on his return is some time within the next 10 to 14 days, he says.
"That's probably the quickest (timetable), barring any kind of setback," said Cooper. "With all the shoulder exercises I'm doing, I feel like it will be no time before I'm back in Daytona. It's just a little flare-up. They're having me do pretty much every shoulder exercise in the book out here."