An ESPN spokesman issued a statement Thursday, saying: "We stand by our reporting."
On Aug. 4, ESPN's "Outside the Lines" first reported the NCAA was investigating whether Manziel was paid for signing hundreds of autographs on photos and sports memorabilia in January. In that report, two sources said Manziel agreed to sign memorabilia in exchange for a five-figure flat fee during his trip to Miami for the BCS National Championship.
Sharp wrote in his email that he recently supported Manziel at a school function.
"While I did confirm that it was a personal view, my motivation was based on the fact we have had ongoing and productive dialogue with the NCAA during their investigation, as required," Sharp wrote. "However, some members of the media have chosen to declare #2 guilty with no evidence whatsoever.
"Darren Rovell of ESPN, who broke this story, has been duped before. During his report on Johnny Manziel, he cites unnamed sources who refuse to provide an interview or any tangible proof. In fact, his 'named source,' Drew Tieman (initially referred to as the broker), was reportedly booked twice for possession of marijuana and placed on four years probation. He [Tieman] has taken down his Facebook page, changed his telephone number and is refusing attempts to be interviewed by the NCAA. It is surprising that the nation's largest sports channel would support publication with this lack of corroboration."