Angels pitcher Garrett Richards’ elbow is found to have healed further

An ultrasound examination of Garrett Richards’ right elbow Wednesday demonstrated additional healing in his torn ulnar collateral ligament, and the Angels will begin stressing his elbow with internal-rotation exercises to test his readiness to resume throwing.

Richards received a stem-cell injection into his elbow ligament May 16 in an attempt to avoid Tommy John surgery. His first ultrasound examination six weeks later showed enough improvement that he was pronounced asymptomatic. Wednesday’s news gave the 28-year-old right-hander more hope.

“Stem cells are a remarkable thing,” Richards said. “The body heals itself, so that’s awesome. We’re not out of the woods yet, but today’s a good day.”

The plan is for him to receive one last ultrasound exam within two weeks, after the stress tests. If that shows the same degree of healing, he will then throw.

“Basically, we want to gauge how the elbow responds to the exercises right now,” Angels General Manager Billy Eppler said. “I think you can learn a little more from testing it and putting the stress on than you can throwing 60 feet at 50 or 60% effort.”

Richards has long felt fine, pain-free for weeks and generally hopeful, “but you don’t know anything until you have it imaged,” he said.

Eppler said he has grown more optimistic Richards could avoid surgery. But both men agree that Richards needs to face hitters by November to be certain.

“I think it’s a must,” Richards said. “I don’t think there’s any way I can not pitch in a competitive setting before this season’s over, whether that’s in the instructional league, the fall league or whatever.”

Instructional league play lasts one month and begins in mid-September. The Arizona Fall League begins in October. Richards would not ordinarily be eligible, but the Angels could petition the league to allow him to appear.

Short hops

Right-hander Nick Tropeano elected to undergo Tommy John surgery after consulting three doctors about his ulnar collateral ligament tear, suffered last month. He has not decided on a surgeon, according to Eppler. Tropeano will aim to return for 2018. … First baseman C.J. Cron will travel to Arizona when the Angels leave for their three-city, nine-game road trip after Thursday’s 4 p.m. game against Oakland. He remains at least a week away from a rehab assignment, Angels Manager Mike Scioscia said. … The Angels released outfielder Craig Gentry, who signed a one-year deal for $1 million in December. He exercised his right to refuse a minor league assignment.

pedro.moura@latimes.com

Twitter: @pedromoura