Right-hander Wilfredo Boscan will be recalled from Triple-A Indianapolis on Tuesday night and make his first Major League start against the Giants.
Righty Curtis Partch was optioned to Indianapolis to make room for Boscan on the active roster.
Boscan has a 2.92 ERA in five relief appearances for Pittsburgh this season, earning his first Major League victory on May 23 against Colorado. He is 5-5 with a 3.33 ERA in 10 appearances (nine starts) for Indianapolis.
Cash Kruth is a reporter for MLB.com. Follow him on Twitter at @cashkruth.