Eflin felt soreness in the elbow in his last start in Triple-A.
But Quinn has an injury to the UCL (ulnar collateral ligament) in his left elbow. He will receive a second opinion from Dr. James Andrews.
It is Quinn's non-throwing elbow, so it could be worse. But it is unclear how much time Quinn might miss because of it. Quinn, the Phillies' sixth-ranked prospect, according to MLBPipeline.com, entered the season hoping to stay healthy. Since 2012, he has missed time because of a fractured right wrist, a ruptured right Achilles, a strained left quadriceps, a concussion and a strained left oblique.
Quinn has not played since May 28, when he hurt himself sliding into third base in a game against Louisville. He is hitting .274 with eight doubles, two triples, three home runs, 13 RBIs, 10 stolen bases and a .739 OPS in 45 games.
Fans had been wondering about a potential promotion to the Phillies for Quinn, but it seems those plans are on hold for the foreseeable future.
Todd Zolecki has covered the Phillies since 2003, and for MLB.com since 2009. Follow him on Twitter and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.