Angels pitchers Garrett Richards and Andrew Heaney get mixed reports after elbow exams

Ultrasound exams on injured Angels pitchers Garrett Richards and Andrew Heaney found nothing conclusive for either man on Monday, but Richards’ results were more encouraging than Heaney’s, according to the team.

Both starters visited Dr. Steve Yoon in Los Angeles, where they each received a stem-cell injection to try to repair partial ulnar collateral ligament tears faster than surgery.

Heaney, a 25-year-old left-hander, received his in April. Richards, a 28-year-old right-hander, had his in May. Monday’s test was Heaney’s second ultrasound to check for healing within his ulnar collateral ligament; it was Richards’ first.

Angels General Manager Billy Eppler said Richards’ exam showed his partial tear is healing as hoped. He was pronounced asymptomatic. Eppler said Richards will rest for six more weeks and be reevaluated. At that point, three months from the initial injection, he could resume throwing.

Heaney’s ultrasound did not encounter “progressive healing that would’ve been optimal.”

“At this point, he will continue to allow the properties of the injection to work for the next couple weeks,” Eppler said. “We will evaluate him close to the All-Star break and go from there.”

The Angels have not set a deadline for when the two pitchers must resume throwing before their 2016 season is shelved.

“In both cases, we are taking a conservative route,” Eppler said. “In one case, it’s shown a little more progression than in the other, but neither situation’s at a point of a decision making. Organically, this is going to declare itself one way or another before season’s end.”

The Angels did not make either pitcher available to speak to reporters before Monday’s game. Eppler was unworried about the possibility that the delays could jeopardize part of either pitcher’s 2018 campaign if surgery proves to be required.

The Angels received more injury news, on left-hander C.J. Wilson, who has pitched in one competitive game this season, May 25 for Class-A Inland Empire. Before and after that four-inning stint, he has been bothered by shoulder tendinitis. The 35-year-old will seek an additional doctor’s opinion on the problematic joint.

“It seems like it’s not firing the way he wants it to fire,” Eppler said.

Wilson’s five-year, $77.5-million contract expires at season’s end.

Short hops

Setup man Joe Smith felt more overall soreness than he anticipated following his eight-pitch inning on rehab assignment for Inland Empire on Sunday. He’ll throw again there Wednesday. If he feels all right, he’ll likely be activated Friday in Boston. … Infielder Cliff Pennington underwent an MRI exam on Monday that showed his strained hamstring is not fit to continue baseball activities. … Left-hander Tyler Skaggs (recovering from elbow surgery) started for Inland Empire on Monday, his first game action since April 20. Skaggs, who had been in extended spring training, remains at least a few weeks away from returning to the majors. … The Angels’ signing-bonus discussions with second-round pick Brandon Marsh, a Georgia high school outfielder, are “ongoing,” Eppler said.

pedro.moura@latimes.com

Twitter: @pedromoura