Oscar McDonald during a Carlton training session at Ikon Park on December 6, 2021. Picture: AFL Photos

CARLTON defender Oscar McDonald will miss the rest of the season after his back stress fracture failed to respond well to treatment. 

McDonald hasn't played since being subbed out of the Blues' round two clash at half-time with back spasms. 

The former Demon joins fellow talls Marc Pittonet, Mitch McGovern and Harry McKay on the sidelines. 

MEDICAL ROOM Check out the full injury list

With McDonald moved to the inactive list, the Blues will now have two available list spots that can be filled at the NAB AFL Mid-Season Rookie Draft on June 1. 

Oscar McDonald (left) with Carlton teammates at training on May 6, 2022. Picture: AFL Photos

Carlton head of football Brad Lloyd said the club had spent weeks exploring ways to allow McDonald to increase his training loads, to no avail. 

"Oscar worked as hard as anyone over the summer to earn a spot in our 22 for the start of the season, that is what makes this news even more disappointing," Carlton Head of Football Brad Lloyd said.

"For nearly two months we explored every possible avenue available to get Oscar up and going however it wasn't to be. We will now put our focus in making sure Oscar is able to rehabilitate the injury over the remainder of the season."

05:38