Defenseman Brian Dumoulin was placed on injured reserve.
Warsofsky, 26, is joining the Penguins for the second time this season. Earlier this year, he was plus-1 in four NHL appearances with Pittsburgh.
The 5-foot-9, 170-pound Warsofsky leads WBS defensemen in scoring this year with 21 points (5G-16A) in 20 games. He is one of just six AHL blueliners averaging a point per game.
Warsofsky, a Marshfield, Massachusetts native, ranks fourth in the AHL, and first among D-men, with a plus-16. His four power-play goals are tied for fourth among AHL blueliners.
Warsofsky comes to Pittsburgh riding a four-game point streak (2G-6A-8PTS) and he has at least one point in nine of his past 10 games (3G-12A-15PTS).
Over the past two seasons, Warsofsky has 27 points (7G-20A) in 37 AHL games with WBS and one goal in 16 NHL contests with Pittsburgh.
