Mantha (lower body) was designated for injured reserve Thursday, Wes Gilbertson of the Calgary Sun reports.

Mantha was injured in Tuesday's clash with Montreal and now should be expected to be sidelined for at least the Flames' next three contests. Prior to getting hurt, the 30-year-old winger was finding his stride with three points in his last four outings. Barring a long-term injury, Mantha should still be capable of pushing for the 40-point mark after racking up 44 points in 74 regular-season outings with Vegas and Washington last year.