Drafted in round three out of UCLA in 2010, he put up very impressive stats pitching for Single-A Frederick and Double-A Bowie in the 2011 season and seemed to be on a fast track to Baltimore. But since that August, he has had two shoulder surgeries and one setback, and now he finds himself yet again on a long road back to the pitcher's mound.
In 38 2/3 innings over the 2010 and 2011 seasons between short-season, Single-A Aberdeen, Frederick and Bowie, Klein went 4-1 with an ERA of 0.93. He walked just seven and fanned 47. Late in that 2011 season, he was set to be promoted from Bowie to Triple-A Norfolk and a call-up to Baltimore in September seemed quite possible.
But the right-hander, who had arthroscopic shoulder surgery while at UCLA in 2009, developed shoulder issues again. In August 2011, Klein underwent labrum surgery performed by Dr. Lewis Yocum.
"Rehab went well (after that procedure), but for some reason when I started throwing it didn't feel right. I was feeling the same pain as before surgery. This was during spring training this year and we ended up shutting it down," he said.
The bad news Klein got was that his surgically repaired shoulder needed to be cut on again and this time he went to see Dr. Craig Morgan of Wilmington, Del.
"Dr. Morgan found that the one anchor I had put in (during the previous August surgery) was torn and my labrum was re-torn somehow," Klein said. "No one could really give me a straight answer as to how I did that, either in the rehab process or when I started throwing. Dr. Morgan said my biceps tendon had too much room to move and was tugging on my labrum, causing it to tear again. So he put three more anchors into my labrum and put a stitch into my biceps interval and tightened that up. That was the surgery I had on April 16 (of this year).
"It was about nine months past my (earlier) surgery and, at that point, I should have been throwing bullpens and feeling pretty good, but I couldn't get past 70 feet without feeling pain in my shoulder (during spring training)."
Klein said he won't play the blame game and doesn't feel that anything went wrong with that first surgery with Dr. Yocum.
"I'm told this is not the first time an anchor has torn," Klein said. "They said maybe it didn't settle right. I don't think he made a mistake in surgery. Something happened during rehab or it didn't set right from the beginning.
"The anchors are indicative of how big the tear is. The first time the tear wasn't that big. This one (in April), the anchor was ripped and the tear was bigger so they put three (anchors) in."
After two surgeries eight months apart, believe it or not, Klein's shoulder issues were not completely over.
"Once they cleared me to do exercises about two months out, it just didn't feel right," he said. "When I got into the grind of rehab, it started flaring up again. I'd take a step forward and then two steps back. I could feel it with simple exercises or even just driving. I went back to see Dr. Morgan and he felt it was bursitis and I got a cortisone shot (in late June).
"At that point, (Orioles minor league medical coordinator) Dave Walker and I decided it would be better for me to come back to California and give my shoulder a rest for about a month. Everything we were doing wasn't taking.
"That rest helped a lot. I started doing exercises again after about a month. It has been about three to four months since then and I've progressed really well. Now I've been doing rehab in LA for about the past month and it's feeling pretty good. Much better now. I've been doing heavy rehab for about six weeks."
Klein was a good enough high school quarterback in Anaheim, Calif., to get college scholarship offers but he instead went to UCLA to play baseball. Klein came back from his arthroscopic procedure from 2009 to pitch well enough for the Orioles to select him with the 85th overall pick in 2010.
But now, after two surgeries within a year, he realizes the odds of a full comeback have gotten longer.
"Every time you have surgery, the statistics say the percentages of you coming back go down," he said. "But you can't really think about that. I'm just doing everything I can to start throwing again. It's been a tough year and a half. To go from throwing so well in 2011 to this.
"No one is to blame in any of this. I did everything to come back from that first surgery. We just don't know what exactly happened."
Klein is hopeful he can begin some light throwing around Dec. 1 and, if all progresses well, begin to build up arm strength from there.
During our phone conversation Wednesday, Klein sounded upbeat despite what the last 14 months have thrown his way. But at this point he is not about to look too far down the road and try to predict or project when he can return and at what level of effectiveness. He's been through too much for that and just is taking it day by day and step by step right now.
"I haven't really been on a mound in over a year," he said. "It's tough. Two surgeries in less than a year is no fun. But I'm hanging in there and doing everything I can to get back on the field. It's not like I did anything wrong. I did all my rehab right. But to hear I re-tore my labrum was tough to deal with. Now I am doing everything I can to get back.
"I'd like to be well into throwing and throwing hard by spring training and be close to healthy by then but we'll just have to wait and see how these next few months go. Once I can get back on the mound with no pain, I'm very confident I can have success."