- The San Francisco Giants placed right-handed starter Matt Cain on the 15-day DL and will recall right-hander Jake Dunning from Triple-A Fresno, the team announced. Cain, who is off to a slow start with a 4.35 ERA across 31 innings, will likely be on the DL for less than the usual total of 15 days because his stint can be retroactive to April 25, according to the San Francisco Chronicle's Henry Schulman.
- Cincinnati Reds outfielder Jay Bruce will undergo surgery to repair a torn meniscus in his left knee, according to the Cincinnati Enquirer's John Fay and confirmed by ESPN's Keith Law. Our own Tyler Drenon wrote about who will replace Bruce while he's sidelined:
- The Colorado Rockies activated right-hander Jhoulys Chacin from the 15-day DL and placed catcher Wilin Rosario on the 15-day DL, retroactive to May 3, with a viral infection, according to a team announcement. Chacin started for the Rockies on Sunday and allowed four runs on eight hits and five walks across five innings.
- The Oakland A's transferred right-handed starter A.J. Griffin to the 60-day DL from the 15-day DL with a right flexor muscle strain, according to MLB.com's transaction page. Griffin is currently recovering from Tommy John surgery and is out for the remainer of the season.
- The Tampa Bay Rays recalled right-hander Nate Karns from Triple-A Durham and designated right-handed reliever Heath Bell for assignment, the team announced.
- The Atlanta Braves activated right-hander Gavin Floyd from the 15-day DL and optioned Ian Thomas to Triple-A Gwinnett, per a team announcement. Floyd will start in place of Ervin Santana on Tuesday.
- The Cleveland Indians recalled center fielder Nyjer Morgan from Triple-A Columbus and optioned Nick Hagadone to Triple-A to, according to a team announcement.
- The Kansas City Royals activated left-hander Tim Collins from the 15-day DL and optioned right-hander Aaron Brooks to Triple-A Omaha, the team announced.
- The Chicago White Sox activated right fielder Moises Sierra and optioned Frank De Los Santos to Triple-A Charlotte, according to a team announcement.
- The Houston Astros recalled left-hander Darin Downs from Triple-A Oklahoma City and designated left-hander Raul Valdes for assignment, per a team announcement. Downs pitched a inning of scoreless relief in the Astros' 8-7 loss.
- The Toronto Blue Jays purchased the contract of Marcus Stroman from Triple-A Buffalo and optioned Anthony Gose to Triple-A, the team announced.
- The Baltimore Orioles sent David Adams outright to Triple-A Bowie, according to a team announcement.
- The A's claimed center fielder Nick Buss off waivers from the Los Angeles Dodgers and optioned him to Triple-A Sacramento, according to MLB.com's Jane Lee.
- The Los Angeles Angels signed free agent left-hander Dustin Richardson to a minor league contract, according to MLB.com's transaction page.