Kontos (groin) was activated from the 10-day disabled list Thursday, Bill Brink of the Pittsburgh Post-Gazette reports.
Kontos was able to get through a 20-pitch simulated game with no issues Tuesday, clearing the way for him to return before Thursday's series finale against the Cubs. The 32-year-old, who owns a 3.65 ERA through 56.2 innings this season, should immediately return to pitching high-leverage innings for the Pirates.