San Francisco 49ers tight end George Kittle, is set to enter his ninth season in the NFL, recently said that he plans to play in the NFL until "I don't have fun anymore."

San Francisco 49ers All-Pro tight end George Kittle isn't hanging it up any time soon—he just signed a four-year extension with the 49ers after all—but he has a good feeling about how he'll know when it's time to retire from the NFL During an appearance on Bussin' With the Boys,