Alek Thomas' Hamstring Was Not Fully Healed Per Torey Lovullo

The Diamondbacks manager said Thomas had a PRP injection to help promote healing after a setback suffered during his rehab assignment

Arizona Diamondbacks center fielder Alek Thomas (5) catches a fly ball / Joe Rondone/Arizona Republic / USA TODAY

Diamondbacks centerfielder Alek Thomas received a Platelet-rich plasma (PRP) injection today to help address continued swelling in the lower part of his left hamstring tendon. Thomas first went on the injured list for the D-backs on April 1st. He suffered a setback during a recent rehab appearance in Triple-A.

Lovullo indicated this was a continuation of the initial injury, not a new injury. "It was not fully healed," Lovullo said.

Thomas said he began jogging the bases as early as April 19th and later went out on a rehab assignment in Reno from May 3-5. Coming off the field after that last rehab game, Thomas reported some soreness and returned to Phoenix to get an MRI. After several days and getting multiple opinions, the PRP injection became the chosen course of action.

While Lovullo said that they had not been discussing a surgical procedure, PRP injections in the hamstrings are sometimes considered an alternative to surgery for partial tears. When asked if more than one injection was being considered Lovullo could not say. But multiple injections are often part of the treatment plan.

There is no clear timeline for how much longer it will take for Thomas to heal and return. According to Lovullo, while Thomas can do some baseball activities such as range of motion, throwing and standing in the box to see pitches, he's going to be limited for the immediate future.

"Clearly he can't get on his legs and do the running that we want him to... probably standing up and firing on his legs when he's hitting, we're going to have to hold off on." Whenever Thomas does heal he will need to go back out on a rehab assignment again, Lovullo said

Corbin Carroll has been manning center field in Thomas's absence with Jake McCarthy, Pavin Smith, and Randa= Grichuk splitting time in right field.

Geraldo Perdomo (knee surgery, torn meniscus) is starting to ramp up baseball activities. He took batting practice in the cage and then went out and took some live at bats. He had a day off from defensive work and throwing, which he had already started prior to today. He will do defense work tomorrow.

There is no definite timeline for Perdomo's return, but Lovullo recently said he hoped the shortstop would be back before the end of May. He will also require a rehab stint before returning.

Merrill Kelly is still in the treatment phase of his rehab. There is no specified time for his throwing program to begin.

Eduardo Rodriguez (left shoulder strain) began a throwing program last weekend and is throwing out to 75 feet.

Miguel Castro and Luis Frias, both with shoulder inflammation, are both throwing out to 90-100 feet.