Peyton Manning says he's so mad at HGH report he'll 'probably' sue Al Jazeera

Peyton Manning told MMQB's Peter King that he will "probably" sue Al Jazeera for its report released Sunday that Manning, among several American sports stars, used human growth hormone, or HGH. Manning vehemently denied the report, according to King, and when explaining why he might sue said, "I'm that angry."

Al Jazeera's source was Charlie Sly, who worked at an Indiana anti-aging clinic, the Guyer Institute, in 2011. According the report, Sly mailed HGH to Manning's wife, Ashley, while Manning was recovering from multiple neck surgeries. Manning did not dispute the deliveries to his wife. He also refused to discuss any medical condition his wife might have been dealing with.

King also said that Al Jazeera confirmed to him that Sly worked at the clinic in 2011. Sly recanted his account given to Al Jazeera on Saturday night, saying that he did not begin working at the institute until 2013. Dr. Dale Guyer, who operates the clinic, said the same thing.

The Al Jazeera report implicated athletes across the NFL and Major League Baseball. Current NFL players named in the report include Clay Matthews and Mike Neal of the Green Bay Packers, Julius Peppers of the Chicago Bears, James Harrison of the Pittsburgh Steelers and free agent Dustin Keller. MLB players include Ryan Howard of the Philadelphia Phillies and Ryan Zimmerman of the Washington Nationals.

HGH has been a banned substance in the NFL since 2011, but the league did not begin testing for it until 2014.