The Pirates recalled Barco from Triple-A Indianapolis on Sunday.
Barco will be up with the Pirates for the fourth time this season and owns a 7.36 ERA and 2.11 WHIP in 14.2 innings over six appearances with the big club. The left-hander most recently tossed a six-inning shutout for Indianapolis last weekend and could be called upon to cover multiple innings of relief during Sunday's game against the Red Sox. Lake Bachar will be making a spot start Sunday, but he's expected to be in line for a restricted workload after making his first four appearances with Pittsburgh as a reliever.