The Washington Football Team is placing quarterback Ryan Fitzpatrick on injured reserve to the hip injury he suffered Sunday, coach Ron Rivera said Monday.

Taylor Heinicke will start at quarterback on Thursday night against the New York Giants and Kyle Allen will be his backup.

Fizpatrick is getting second opinions to determine severity of the injury, Rivera said, adding that he doesn’t yet know how long he’ll be on IR. Fitzpatrick had an MRI on Monday to see whether he suffered a hip subluxation and to determine the severity of the injury.

Fitzpatrick left Sunday’s 20-16 loss to the Los Angeles Chargers in the second quarter after being leveled by Chargers linebacker Uchenna Nwosu.

Heinicke, a fan favorite after his strong showing in a playoff loss to the Tampa Bay Buccaneers, replaced Fitzpatrick. He finished 11-for-15 for 122 yards and a touchdown.

ESPN’s Jeremy Fowler and John Keim contributed to this report.