SPRINGFIELD, Ill. (AP) — Gov. J.B. Pritzker has a hairline fracture in his left femur and a doctor has ordered rest for four to six weeks.

The Democrat’s office said Thursday that Pritzker doesn’t know how the injury occurred. It was not a recent injury. But pain in his knee became more significant in recent weeks while attending public events where he stood or walked long distances. He made several visits to the state fairs in Springfield and DuQuoin.

A statement says that Pritzker is in “good spirits” and will remain “fully engaged” in government business. He will receive frequent updates from his staff and agency heads.

The statement says Pritzker is in otherwise good physical health.