Alex Gilbey could miss the remainder of the season with an ankle injury.
The 24-year-old limped out of the action against Yeovil on March 23, and while manager Paul Tisdale was hopeful of an immediate return, has not been seen since.
With five games remaining, Tisdale confirmed Gilbey will miss the trip to Tranmere Rovers on Saturday, but admitted he does not know when the midfielder will be back.
"He won't be fit," Tisdale confirmed. "He'll be out for at least this game and more. It's a lot more prohibitive than we first though – we'd hoped when he limped off against Yeovil that he'd be back the next week. It isn't the case. He will be out and I'm not sure when he will be back."
Gilbey was spotted behind the dugout during Saturday's 2-0 defeat to Lincoln City alongside fellow injured Dons Baily Cargill, George Williams, Robbie Simpson and Mathieu Baudry, with Jordan Moore-Taylor also missing from action.
Tisdale though does not want to look at injuries as an excuse, instead as an opportunity for the rest of his squad to prove themselves as the race for automatic promotion nears a conclusion.
He said: "Sometimes that's how it works. I always value the ability of the squad, players who are capable and respectful of each other. We've had injuries but we don't look beyond the next game. I trust them all, and I have faith in them all. It's all about finishing where we want to in the league and the 11 on the field who do it.