Heavyweight champion Mike Tyson is considering retiring from boxing by the end of the year, the New York Daily News reported Friday.

The News quotes an unidentified friend of Tyson's as saying, "He's talking retirement. He's saying after the (Frank) Bruno fight (set for Sept. 3 in London), that's it. He's said it a few times."The friend also spoke of a possible lack of motivation for Tyson, who has been surrounded by reports of marital trouble as well as problems with manager Bill Cayton as he prepares for Monday's title defense against undefeated Michael Spinks.