The Ottawa Senators say Clarke MacArthur has been diagnosed with a concussion after he was hit at a scrimmage at Sens Fan Fest Sunday morning.
MacArthur was struck against the boards by prospect Patrick Sieloff during the game while fans looked on.
Sens General Manager Pierre Dorion says he's heartbroken for his player.
"There's a level of concern anytime anyone has a concussion. In Clarke's case he's had a history," he said. "We held him out last year even though he was cleared to make sure that he'd be okay for this camp."
On Saturday, the Sens announced Mark Stone has also been diagnosed with a concussion sustained during a practice scrimmage.
It's not clear when either player will be back on the ice with the preseason getting underway Monday,