"Liam's injury is worse than we feared," Robins boss Gary Johnson told the Bristol Evening Post.
"He went for the scan on Monday and it showed up ligament damage. He will be out for a minimum of three weeks and maybe longer."
It's one of the most exciting nights of the football calendar as the FA Cup 3rd Round draw is taking place at around 1915 on Monday evening.
Premier League and Championship sides will be paying close attention to BBC Two on Monday night as the two top
Manchester City host Celtic in their final Champions League Group C game on Tuesday.
Leicester manager Claudio Ranieri admitted on Saturday that everything is wrong with the Premier League champions' defence of their title
The latest gossip and rumours from the newspapers and online:Arsenal target JULIAN DRAXLER has reiterated his wish to leave Wolfsburg
The title-race heat went up a notch as Chelsea made their mark, Arsenal continued to put the pressure on the