Boscan was called up from Triple-A Indianapolis on Thursday, Bill Brink of the Pittsburgh Post-Gazette reports.
Boscan has been impressive in seven starts with the Triple-A squad, posting a 2.48 ERA with only four walks in 40 innings pitched. This was good enough to warrant a callup to the big leagues and a spot on the 40-man roster, although he'll likely fill a long relief role rather than a starting role for Pittsburgh. Left-hander Cory Luebke was optioned to Triple-A to make room for him on the major league roster, while Elias Diaz was transferred to the 60-day disabled list to make room for him on the 40-man roster.