After the Denver Broncos voiced their support for Peyton Manning as the quarterback was linked to an Al Jazeera report claiming several professional athletes received human growth hormone and hormone supplement Delta-2 from the Guyer Institute, an anti-aging clinic based in Indianapolis, the Washington Nationals followed suit on Sunday, issuing a statement in support of veteran infielder Ryan Zimmerman, who was also named in the report. The release said the Nationals organization does not find “Al Jazeera’s report — which has already been recanted by their source — to be credible.”

The Al Jazeera documentary, scheduled to air Sunday night, claims that in addition to Manning and Zimmerman, Philadelphia Phillies slugger Ryan Howard and other athletes used performance enhancing drugs. Manning fired back immediately, calling the report “garbage” and appearing on ESPN Sunday morning to vehemently deny the allegations in an interview with Lisa Salters. Two people familiar with the thinking of the NFL and the MLB told the Washington Post both leagues will investigate the report.

Both the Broncos and the Indianapolis Colts released statements supporting Manning.

“Knowing Peyton Manning and everything he stands for, the Denver Broncos support him 100 percent,” the Broncos wrote. “These are false claims made to Al Jazeera, and we don’t believe the report.”

According to information Al Jazeera provided to the Huffington Post, the report uses information obtained by British hurdler Liam Collins, who “went undercover in an attempt to expose the widespread nature of performance-enhancing drugs in global sports.”

Collins obtained information from pharmacist Charlie Sly, who told Collins the clinic supplied HGH to Manning’s wife and Delta-2 to Zimmerman and others. Sly recorded a video Sunday morning saying “there is no truth to any statement of mine that Al Jazeera plans to air.”