The PRP injection means that Buchholz has to stop throwing altogether for an unspecified period of time, which will halt him from engaging in the light catch he had been doing in recent days.
"The diagnosis was consistent," said Red Sox manager John Farrell. "And at the time Clay was examined in Boston, [doctors found] no ligament issues, and the injury is still the same flexor tendon area.
"At the time there was discussion of a PRP injection, which he opted not to go through. Then upon the second opinion today, the diagnosis is still consistent but Dr. Andrews talked to Dr. [Peter] Asnis [the team's head orthopedic surgeon] back here. Again, he recommended a PRP injection so, as of today, Clay did go ahead with that injection."
The Red Sox are still confident Buchholz will pitch again in 2015.
"Again, to say there's a definitive timeline on when he puts a ball back in his hand is yet to be determined and that will be at further recommendation of Andrews, and as we get all the information and continue to put it together," Farrell said.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.