The Red Sox selected Martinez's contract from Triple-A Worcester on Sunday, Mac Cerullo of the Boston Herald reports.
Boston optioned left-hander Raymond Burgos to Triple-A to clear room for Martinez, who is up with the big club for the first time this season. Over 34 appearances (nine starts) at Worcester, Martinez produced a 5.46 ERA, 1.27 WHIP and 52:20 K:BB in 62.2 innings. He'll be capable of covering multiple innings in Sunday's game against the Athletics as the Red Sox deploy a bullpen day.