Chelsea have announced via their Twitter feed that John Terry will be out for "weeks rather than months".
Terry was injured in a collision with Liverpool forward Luis Suarez during the 1-1 draw at Stamford Bridge on Sunday and there had been concerns the Blues captain would miss much of the season.
However, on Monday the club said: "MRI Scans reveal no significant damage to John Terry's cruciate ligaments. He will be out weeks rather than months."
The club added on their official website that further tests will take place in the coming days, when the swelling has subsided, to determine more precisely the extent of the injury.
Prior to the announcement, goalkeeper Petr Cech said he was confident the club could cope with Terry's absence.
"We managed to play games without him and we have players who will have a chance to impress," he said. "I have confidence. Obviously, it's a pity we will lose him again but we have a large squad and quality defenders to deal with that.
"It's important to have people who can step up. This is a chance for the others to shine and we are going to deal with his loss for him."
Cech is also upbeat about Terry's ability to get back to fitness quickly.
Cech added: "He knows what it takes to come back in good shape and as soon as possible. He always heals well and he will come back soon. We saw him afterwards and wished him good luck. We hope the danger is not going to be severe and something that will just keep him out for a few weeks maximum."
Information from the Press Association was used in this report.