Phillies manager Rob Thomson said Tuesday that Lazar is dealing with a "mild" oblique injury and is returning to big-league camp to be evaluated, Jayson Stark of The Athletic reports.
The right-hander suffered the injury during the World Baseball Classic, and his availability for the start of the regular season is now in question. Lazar made 36 regular-season appearances for the Phillies last year and had a 4.79 ERA, 1.28 WHIP and 26:12 K:BB over 41.1 innings.