Peterborough United boss Darren Ferguson has said defender Gabby Zakuani missed Sunday's defeat by Blackpool through injury.
The 25-year-old was expected to start at Bloomfield Road, with no suggestion of a setback before the game.
"He's got a problem with his toe he did early against Stevenage [last week]," Ferguson told BBC Radio Cambridgeshire.
"He was never going to be fit for the game but we managed to keep it quiet, we'll see how he is for Millwall."
Zakuani's absence raised concerns among supporters the former Stoke defender was being primed for a move away from London Road.
But the centre-half, who agreed a new three-year contract with Posh in June, has dismissed speculation linking him to other clubs.
"All those rumours are false by the way, no bust up, no transfers," he said on social networking site Twitter.