The Orioles have reinstated outfielder David Lough and optioned right-hander Eddie Gamboa to Triple-A Norfolk.
The move gives manager Buck Showalter a four-man bench for the first time this season.
Lough, who began the season on the disabled list with a left hamstring strain, needed just one minor-league rehab game before he activated.
He played six innings for the Frederick Keys on Sunday, batting leadoff and starting in left field. He was 0-for-2 with a sacrifice fly.
Gamboa gave the Orioles some bullpen insurance on Sunday, but was expected to return to Norfolk to make his scheduled start for the Tides on Monday.
One other item of note, catcher Ryan Lavarnway will wear uniform No. 34 effective tonight. He was wearing No. 60