David Ross (concussion) will begin a rehab assignment Thursday with Double-A Portland.
Blue Jays prospect Sean Nolin is expected to start Friday against the Orioles.
Athletics activated SS Hiroyuki Nakajima from the 15-day disabled list; optioned him to Triple-A Sacramento.
Mariners purchased the contract of C Jesus Sucre from Triple-A Tacoma.
Mariners optioned C Jesus Montero to Triple-A Tacoma.
Royals prospect Yordano Ventura allowed seven runs (six earned runs) on nine hits over 4 1/3 innings in his start Wednesday with Double-A Northwest Arkansas.
Orioles prospect outfielder Henry Urrutia is batting .333/.413/.542 with three home runs and 19 RBI in 25 games with Double-A Bowie.
Orioles prospect Brandon Kline (ankle) has been placed on the disabled list with Low-A Delmarva.