Former Sunderland goalkeeper Craig Gordon admits he could be forced into retirement.
The 30-year-old is without a club after leaving Sunderland at the end of last season.
Two broken arms and a knee injury undermined his latter years on Wearside and the ongoing problem with his leg has meant he has been without a club this season.
Gordon told Dumbarton's website: "It's very unlikely I will be playing again this season. In fact I'm not sure if I'll play again, so I'm looking to get into coaching as I want to remain in the game.
"I'm not ruling out playing again, but I need to get things in place if the news is not good in that respect."
He added in a number of national newspapers: "I've had a couple of surgeries on it, but it's definitely not back to 100 per cent yet.
"Hopefully I can get back to playing with a bit of pain. It's about getting to a stage where I can get what I need to out of the knee.
"That's part of the reason I wanted to go into coaching, you don't know when the end might come for playing.
"I'm certainly not ready to throw in the towel just yet but it's been a long time and I don't know where I'll be going in the future."