Veteran Adelaide defender Brent Reilly will undergo surgery after fracturing his skull at AFL pre-season training.

Reilly was hurt in a collision on Monday morning and received immediate medical attention.

He was taken by ambulance to the Royal Adelaide Hospital.

“The 31-year-old is conscious and expected to undergo surgery late today,” the Crows said in a statement.

Reilly has played 203 senior games since his 2002 debut.