The 39-year-old Kovalev has played in 1,302 NHL games with the New York Rangers, Pittsburgh, Montreal and Ottawa, with 428 goals and 1,024 points. He was with the Panthers on a tryout contract for training camp, and is expected to be on a line with highly touted rookie Jonathan Huberdeau to open the season.
Kovalev last played in the NHL during the 2010-11 season. He spent last season in Russia's KHL.
Panthers general manager Dale Tallon says Kovalev still has "great skill and vision."
Also Friday, Panthers coach Kevin Dineen announced the selection of defenceman Ed Jovanovski as the franchise's seventh captain. Stephen Weiss and Brian Campbell will serve as alternate captains.