"This is just a resource that I was going to exercise before surgery," Richards said. "Some guys have had some success with it. The way my timetable lines up, as far as being back by 2018 if I did have surgery, is not any different if I have surgery now versus a couple of months from now. This is just something that was an option, and I decided to take it."
Richards is undergoing the same treatment as his teammate, fellow starter Andrew Heaney, who will be evaluated in hopes of restarting a throwing program around the middle of June.
Stem-cell therapy involves extracting stem cells from a patient's fat tissue or bone marrow -- it was bone marrow for Richards and Heaney -- then injecting it into the damaged UCL so that it heals. Richards will be evaluated in six weeks. If he does return this season, it probably won't be until August, at the earliest. But this gives him a shot to pitch all of next season, too.
"I wasn't in pain before I got hurt, before I started having these symptoms," Richards said. "It's hard for me to just have surgery when I don't feel like something is surgically required. Even the few days before I had this injection, my arm felt fine. No pain, no nothing. I felt like I could go out and play catch last week. The fact that it wasn't killing me was kind of telling me, 'You have to listen to your body; maybe this is something where I can avoid surgery.'"
Richards didn't prematurely exit a start with excruciating discomfort in his elbow, like other pitchers have when they tear their UCL. The 27-year-old right-hander made six starts, and averaged 96 mph on his fastball during his last outing in Arlington on May 1.
He believes the damage on his UCL happened over time.
"I'm still throwing 95," Richards said. "There's got to be something that we're not seeing."
Richards had his medicals reviewed by numerous physicians, including Dr. James Andrews, Dr. David Altchek, Dr. Neal ElAttrache and those in the Angels' medical department. Richards plans to make a quick decision on surgery upon his evaluation around early July.
"This is something I'm not going to let linger on," Richards said. "If it's not working, we're going to get surgery. But if it works, then it works."
• The Angels are still finalizing details with veteran starting pitcher Tim Lincecum, who has agreed on a Major League contract. The deal is still pending a physical, but could be announced before the weekend. Lincecum, who hasn't pitched since June, would probably need three to four weeks before he's ready to face Major League hitters. The Angels have four injured starting pitchers and will give him a chance.
• Angels closer Huston Street threw a 25-pitch bullpen session Wednesday, his first since landing on the disabled list with a left oblique strain on April 28. Street will throw another bullpen session Friday and believes he's "close." The 32-year-old right-hander is targeting a return by late May or early June, but will probably pitch some games in the Minor Leagues before being activated.
• The Angels released veteran lefty reliever Neal Cotts. Cotts exercised the May 15 opt-out on his Minor League contract Monday, giving the Angels 48 hours to either add him to the active roster or grant him his release. The 36-year-old has a 3.96 ERA, a 1.35 WHIP and a 2.17 strikeout-to-walk ratio in his 10-year Major League career. He had a 3.29 ERA, a 1.10 WHIP and a 4.33 strikeout-to-walk ratio in Triple-A.