The NFL will begin to find out exactly how clean its league is on Monday.

NFL.com obtained a copy of a letter that NFL Players Association president Eric Whitson wrote to the players outlining that testing for human growth hormone is set to begin after today's games.

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The league and the NFLPA agreed on a new drug policy on Sept. 19.

"As you know, the new Performance Enhancing Substances Policy includes HGH testing. Testing for HGH will begin on Monday, October 6th," NFLPA president Eric Winston wrote in a letter to players. "Each week of the season, 5 players on 8 teams will be tested. No testing will occur on game days. We negotiated to ensure that the methodology of testing be conducted in the most professional and safest manner for players. Importantly, after three years of negotiating, players won the right to challenge any aspect of the science behind the HGH isoforms test in an appeal of a positive test.

"For the first time in the history of the NFL, our new collectively bargained policies usher in a neutral arbitration process for appeals of positive drug tests. Until these policies were negotiated, the Commissioner or his designee (an NFL employee) had jurisdiction over all appeals. Your Executive Committee and Player Representatives fought extremely hard to achieve these gains to ensure your fair due process rights.

" ... Importantly, after three years of negotiating, players won the right to challenge any aspect of the science behind the hGH isoforms test in an appeal of a positive test.

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When the original agreement was reached, ESPN reported, it stated that the appeals process would be heard expeditiously because of improved procedures under the policy.

The first offense for a positive PED test is a six-game suspension, for steroid, stimulant or HGH is a four-game suspension.

The first offense for a substance abuse is entrance in the league's drug program. ESPN outlined the list of punishments for each offense.

How the appeals process affects the testing as well as the players' discipline will be closely monitored. If the players wn appeals on a regular basis, the program could turn into another black eye for the program.

How often do you think the players will be able to appeal their positive tests with success? Comment below or tell us @SportsWN.