Denver Broncos quarterback Peyton Manning (18) watches from the sidelines...

Denver Broncos quarterback Peyton Manning (18) watches from the sidelines during the second half of an NFL football game against the Kansas City Chiefs, Sunday, Nov. 15, 2015, in Denver. Credit: AP / Joe Mahoney

Despite vigorous denials by Broncos quarterback Peyton Manning and others tied to HGH use in an Al Jazeera story aired over the weekend, the NFL will investigate the matter, according to a league executive.

“We are reviewing the matter,” NFL spokesman Brian McCarthy said Monday. “Our procedure is to follow up on any information that potentially involves a violation of this nature.”

McCarthy did not indicate any timeline for the investigation.

Manning, three members of the Green Bay Packers — Clay Matthews, Julius Peppers and Mike Neal — and Steelers outside linebacker James Harrison were all named in the report. Also implicated were Major League Baseball players Ryan Howard of the Phillies and Ryan Zimmerman of the Nationals.

According to the report, Manning’s wife, Ashley, received shipments of HGH that were allegedly used by Manning to recover from a series of neck surgeries that forced him to miss the entire 2011 season. Charlie Sly, who once worked for the Guyer Institute, an anti-aging clinic in Indianapolis, told the network of Manning’s involvement, and suggested that the quarterback used the HGH that was shipped to his wife.

Sly later recanted his statement.

“Any recordings of me were made without my knowledge or consent,” Sly said in a statement posted Saturday night on YouTube. “The statements . . . are absolutely false and incorrect. I am recanting any such statements.”

Manning vehemently denied the report, calling it “garbage.” He also said on ESPN that he has never used HGH. The performance enhancing drug was banned by the NFL in 2011 when the NFL and the NFL Players Association signed a 10-year Collective Bargaining Agreement. Testing for HGH didn’t begin until 2014, and no players have tested positive.

“It stings me that whoever this guy is is insinuating that I cut corners, that I broke NFL rules in order to get healthy,” Manning said. He added that he went to the clinic in cooperation with Colts medical staff, which had recommended he receive treatment there for his neck condition.

Matthews said after Sunday night’s game against the Cardinals that the report was “100% falsified, fabricated information. I don’t know who this guy is. I couldn’t tell you what he looks like. I’ve never talked to him. I’ve never communicated with him. To bring my name up like that — which appears to be out of thin air — it’s [expletive], for lack of a better term.”

Dr. Dale Guyer, founder of the anti-aging clinic, said in a statement on Sunday that that he has “no reason to believe these allegations are based in fact or have any truth. I can say with absolute certainty that they are not.”

Guyer added that Sly was “never an employee of the Guyer Institute and his brief three-month internship occurred in 2013, during which time Peyton was not even being treated or present in the office. I think it is obvious that Mr. Sly has fabricated this whole thing for reasons I cannot fathom.”

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