Rangers midfielder Lee McCulloch is on standby to play as an emergency central defender in their opening UEFA Champions League group clash at Stuttgart.
McCulloch could be needed as veteran David Weir has an ankle problem.
With little options available to him, Gers boss Walter Smith has confirmed that McCulloch could be used in defence.
"Davie is a major concern now," Smith told the Daily Record.
"He suffered the injury on Saturday and although a scan showed there is no lasting damage he is struggling with heavy bruising.
"It's causing him a fair bit of discomfort and it's a case of whether or not he feels able to get through the match.
"Right now I'd have to say he is doubtful but we hope he makes it because he is such an important player.
"If he is unable to play then Lee McCulloch will come in as his replacement."