RICHMOND'S No.1 draft pick Sam Lalor will undergo surgery on a fractured jaw after also suffering a concussion on Monday.
Lalor was involved in a heavy collision during the Tigers' match simulation against West Coast at Mineral Resources Park.
He was assisted off the ground before the Tigers confirmed he had suffered a concussion, but further assessment on Tuesday revealed an undisplaced hairline fracture of his jaw
The Tigers are still hopeful Lalor will be available for their round one clash against Carlton on March 13.
The teenager had shown impressive signs against the Eagles, kicking two goals.
Lalor had already been ruled out of the Tigers' AAMI Community Series clash against Collingwood next Wednesday due to being in concussion protocols.
He was hurt when pushed by West Coast's Reuben Ginbey into Eagle triallist Sandy Brock in a marking contest.
Lalor was was assessed by medical staff as he lay on the ground for about one minute, before walking off the field with trainers.