during the AFC Championship game at Sports Authority Field at Mile High on January 19, 2014 in Denver, Colorado.

Here's why the NFL's investigation of Peyton Manning may hit a quick dead end

It's going to be tough for the NFL.

The NFL announced Wednesday that it would investigate HGH allegations against Denver Broncos quarterback Peyton Manning.

Videos by FanBuzz

While the NFL noted it would review records and interviews in its research, per the Associated Press, the league could have trouble acquiring documents to back claims by Al Jazeera America against Manning, according to Forbes.

According to Forbes, since the NFL doesn't have subpoena power, it can't obtain documents pertaining to treatment Manning and his wife may have received unless the Guyer Institute faces civil litigation or is prosecuted.

The only other way the league could get its hands on these documents is if the Mannings relinquished protection under HIPAA, per the report.

Because of the nature of the report and the noted invasion of privacy to Manning's wife — Manning allegedly received HGH from his wife, who reportedly received shipments to the couple's house — it's fair to assume the Mannings won't simply hand out these documents.

Manning has vehemently denied any reports that he's taken HGH. He did however have a great response to the reporter's employer, Al Jazeera America, shutting down.