Martin Kelly is likely to be out of action for a significant period of time after scans revealed he suffered an ACL rupture of his right knee during the match against Manchester United on Sunday.
The England international will now require ACL reconstruction.
Meanwhile, fellow defender Daniel Agger, who was stretchered off the pitch 13 minutes before Kelly limped out of action, has suffered a significant bone bruise to the left knee.
No ligament damage was sustained but further tests will be carried out before it can be established when he will be able to return to training.
To add to Brendan Rodgers' woes, Fabio Borini has considerable swelling to the inner aspect of his right ankle though no fracture was detected on the X-ray.
The club's medical staff will wait for the swelling to reduce before an MRI scan can take place tomorrow to assess any soft tissue damage and determine when he may be able to return to playing.
Martin Kelly has been ruled out until 2013 after it was confirmed the Liverpool defender has ruptured the anterior cruciate ligament in his right knee.
Kelly will undergo a reconstruction process of his ligament which Liverpool say will require a 'significant period' on the sidelines.
Agger sustained 'a significant bone bruise to the left knee' and, although there is no ligament damage, further tests will be required to discover when he will return to full fitness.
Borini has 'considerable swelling' to his right ankle but an X-Ray did not find any fracture.