Kovalev signed a one-year contract with the Panthers that Bob McKenzie is reporting is worth $1 million and also contains bonuses for games played.
Kovalev came to camp with Florida on a tryout contract after playing last season in the Kontinental Hockey League. He last played in the NHL at the end of the 2010-11 season with the Pittsburgh Penguins.
Teams must announce their 23-man rosters for opening night by 5 p.m. ET Friday.