When asked by ABC's Katie George about Notre Dame holding off a furious Florida State rally, Kelly replied, "I'm in favor of execution. Maybe our entire team needs to be executed after tonight. We just didn't execute very well."
The ninth-ranked Fighting Irish led 38-20 entering the fourth quarter but were outscored 18-0 in the final 13:42 of regulation.
During the Buccaneers' inaugural season in 1976, when the team went 0-14, McKay once was asked about his team's execution. He famously replied: "I'm in favor of it."
"It's an old John McKay quote," Kelly told reporters in Tallahassee. "I was kidding. It was tongue-in-cheek. It wasn't funny? ... I was talking and making a joke about it. It was taken serious? Are you people crazy?"
Kelly's comment to ABC immediately generated strong reaction on social media.
Before his Tampa Bay tenure, McKay coached Southern California for 16 seasons and won four national championships. He became a College Football Hall of Famer in 1988.
"It's a John McKay quote that he used after a game," Kelly said. "I was stealing one of his old quotes and being funny, because nobody likes to be funny anymore. If you want to take me to town on that, please do."