Rodgers told BBC Sport “It doesn’t look too good.
“To lose him going into an important stage of the season would be a massive blow,” added Rodgers.
“We would have to do something. Obviously we’ve got Alan Tate coming back this week which is great for us.
“But we would certainly need to reinforce by bringing in another defender.”
Brendan also told the official siteย ย “We won’t know the full extent of the injury until he has the scan, but I will be devastated for him if it’s a bad one.
“I’m gutted for him, especially after getting his first goal of the season today.
“It will be a massive blow for us if it’s serious because he’s a fantastic captain for me and this club – on and off the pitch.
“He’s a great man and a great leader of this group. He’s honest and we speak a lot together. He’s a proper captain who works with his manager rather than against him.
“It’s the same knee as before when he missed nearly the whole season (2006-07) with ligament (ACL) damage.
“Let’s not write him off just yet, but we would certainly need to bring in another defender in the window as reinforcement if he’s out for any length of time.”