BEN Thompson is a major doubt for Millwall's crucial game against Aston Villa on Monday.
Thompson was forced off in the 40th minute of Friday's 1-1 draw with Brentford at The Den, five minutes after being fouled by Henrik Darsgaard, which saw the defender sent off as the last man.
Lions boss Neil Harris said: "At the moment we don't know, it looks like a hamstring so we'll have to see how he is.
"He's been our best player the last couple of months so to lose him is a major blow."
Image: Millwall FC