Rep. Keith Ellison needed surgery Wednesday after falling and injuring his knee during a workout.

Ellison tore a tendon in his left knee when he fell Wednesday morning running on a treadmill in the House gym, spokeswoman Jennifer Gore said.

The Minnesota congressman is out of surgery, but he remained in a Washington-area hospital overnight, she said. It’s unclear when he will be released.

A full diagnosis on the extent of Ellison's injury is not yet available, Gore said.