Lydman practised for a second straight day Thursday and is expected to play against the New York Islanders on Friday after missing six games with an upper body injury.
The Sabres have not disclosed the nature of Lydman's injury. He was hurt during the second period of a 5-3 win at Florida on March 15.
Lydman gives the Eastern Conference-leading Sabres seven healthy defencemen for the first time in six weeks, and his return comes with six games left on Buffalo's schedule. Nathan Paetsch is initially expected be the odd defenceman out even though the rookie has played well in a fill-in role, registering two goals and 22 assists in 59 games this season.
Coach Lindy Ruff hasn't ruled out using Paetsch as a forward in order to keep him active.
The Sabres are quickly getting healthier after forwards Ales Kotalik and Daniel Paille both played their first games in more than a month in a 4-3 win over New Jersey on Wednesday. Both made immediate impacts, scoring a goal each.
Lydman's return would leave the Sabres minus two regulars, right-winger Maxim Afinogenov, who's missed 18 games with a broken wrist, and centre Tim Connolly, who's not played this season while recuperating from post-concussion symptoms. Both players could be back in time for the first round of the playoffs, which start in two weeks.