• Twins righthander Kyle Gibson will undergo Tommy John surgery on Sept. 7, according to Rhett Bollinger, the Twins beat writer for MLB.com. Gibson was diagnosed with a partial tear of his ulnar collateral ligament on Aug. 9.

Gibson was the Twins' first-round pick in 2009 out of Missouri. He was a lock to go in the first 10 picks, but slipped to their spot at 22 because doctors diagnosed a stress fracture in his pitch forearm days before the draft.

He went 3-8, 4.81 with 91 strikeouts and 27 walks over 95 innings this season for Triple-A Rochester.

• Nationals first-round pick third baseman Anthony Rendon will be added to the Scottsdale Scorpions roster, according to Washington Times reporter Amanda Comak.

Rendon's addition gives the team a fearsome middle-of-the-order that also includes Nationals outfielder Bryce Harper and Angels outfielder Mike Trout.