Warning: Video contains coarse language
Maple Leafs defenseman Morgan Rielly could be the suspect, as he may have directed the slur at a referee.
Maple Leafs general manager Kyle Dubas commented on the situation postgame.
"The club is aware of the reports surrounding a homophobic slur used during the Maple Leafs versus Lightning game on Monday night," he said in a statement. "The issue of homophobia is one the Toronto Maple Leafs hockey club strongly condemns and takes very seriously. We are in communication with the NHL and are cooperating fully with their office."