RICHMOND, Va. — Donald J. Trump has some ideas for how to jazz up the Republican National Convention, and he previewed one at a rally here on Friday evening: a “winner’s evening” of sports celebrities and champions addressing the convention rather than politicians.

“We’re going to do it a little different, if it’s O.K.,” he told the crowd. “I’m thinking about getting some of the great sports people who like me a lot.”

After regaling the crowd with the long story of how he successfully courted the endorsement of Bobby Knight, the former Indiana University basketball coach, Mr. Trump rattled off a list of other names of sports figures who he said have supported him. According to the candidate, he also has the support of the star quarterbacks Tom Brady and Ben Roethlisberger; Brian France, the chief executive of Nascar; and Dana White, the president of Ultimate Fighting Championship.