BRENTWOOD -- A California Highway Patrol officer injured Saturday while providing traffic control for the Amgen Tour of California was expected to be released from the hospital today, authorities said.

The CHP Oakland motorcycle officer, who suffered minor-to-moderate injuries, was hit just before 12:30 p.m. by the driver of a Mercedes who made a U-turn and collided with the officer on Marsh Creek Road, just east of Deer Valley Road, CHP spokesman John Fransen said Sunday.

Saturday was the penultimate leg of the cross-state tour, where cyclists were racing from Livermore to the top of Mount Diablo.

"The officer had his lights flashing and was heading toward the intersection to stop traffic so the bikes could go through, Fransen said. "He was struck just before he reached the intersection."

The officer was taken by helicopter to John Muir Medical Center in Walnut Creek.

The officer, whose name is not being released, suffered bad cuts after being thrown from the motorcycle during the crash.

He was expected to be released from the hospital Sunday, Fransen said, because his injuries were not as severe as initially thought.

It was unknown what caused the driver to veer into the officer, but Fransen said the driver of the Mercedes will not face charges because it appears the crash was an accident.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.