Per MLBTR
Baltimore's front office is 'poking around' for No. 5 starter types, according to Ken Rosenthal of The undefeated Orioles have allowed just one run in each of their first four games, but now that Brian Matusz is on the 15-day disabled list with an intercostal strain, the team's rotation is thinner than expected.

Jeremy Guthrie, Jake Arrieta, Chris Tillman and Zach Britton have impressed so far and Brad Bergesen will start against the Tigers tomorrow. It's a promising, but inexperienced group, so it's not surprising to see that president of baseball operations Andy MacPhail has some interest in adding depth.

Potentially available starters include Kevin Slowey, free agent Carlos Silva, Jo-Jo Reyes and former Orioles starter turned Braves minor leaguer Rodrigo Lopez. Though there's no indication that the Orioles are interested in those arms, their names could come up in conversation.
Slowey would be the only one worth getting in my opinion. Slowey is currently relieving for the Twins but has been a starter but has never thrown for that many innings. Slowey could be the swing man for the O's.