Artur Boruc will miss Celtic's UEFA Champions League qualifier with Spartak Moscow due to injury.
The goalkeeper has been struggling with a shoulder problem which has prevented him from featuring in the club's opening two SPL games of the season.
He has travelled with the Celtic squad to Russia for Wednesday's first leg tie in the Champions League third qualifying round.
Boruc was always rated doubtful and Gordon Strachan has now confirmed the keeper will not play.
"I wasn't told how close to fitness he was, I was just told he was out," said Strachan.
The Bhoys will now start with Mark Brown in goal, with the former Inverness keeper having been between the posts for the SPL fixtures against Kilmarnock and Falkirk.
Brown will be making his first appearance in the Champions League, but Strachan is not concerned by the player's lack of European experience.
Asked whether he had any qualms about starting with the 26-year-old for the match, Strachan replied: "None."