The 28-year-old midfielder was surprisingly absent from the squad at Anfield, but it later transpired he had suffered an issue in the 1-0 home win over Crystal Palace last weekend.
Kovacic’s absence extends Chelsea’s injury list to 10 players. However, manager Potter eased fears about the Croatian’s fitness and hopes to have him back to face Fulham in another London derby at Stamford Bridge on February 3.
“He just felt a little bit of tightness in his calf but we are hopeful for Fulham,” Potter told Chelsea TV. “He felt it at the end of the Crystal Palace game.
“That was a blow for us but we coped with it well and that’s a credit to the boys who came in.”
Reece James, Ben Chilwell and Ruben Loftus-Cheek are all back in training as their recovery is managed carefully to avoid re-injury.
They have almost two weeks to prepare for the Fulham match following Chelsea's elimination from both domestic cup competitions by Manchester City.
Wesley Fofana and Raheem Sterling are hoping to return within the next fortnight, with the Blues hoping a remarkable run of injuries eases for the latter part of the season.