OXNARD, California (CBSDFW.COM/AP) – The NFL has suspended Dallas Cowboys defensive end Robert Quinn without pay for the first two games of the regular season for violating the performance-enhancing drugs policy.

Head coach Jason Garrett said the Cowboys trust Quinn and will stand by him in the midst of his two game suspension for performance enhancing substances, CBS 11 sports reporter Keith Russell tweeted from training camp.

Quinn’s agent Sean Kiernan, released the following statement on the matter:

I am extremely disappointed in the NFL for following through with this suspension. In life there are real world instances where a totality of the circumstances must be analyzed. This is one such case.

Rob has a medical history with seizures that requires him to take multiple doses of preventative medication daily to regulate them. He was tested on April 2nd under the NFL Steroid Policy. He failed the test for a substance called probenecid, which is classified as a masking agent under the policy.

He does not take any supplements and took nothing else during this period that would create a positive test for probenecid, in fact, he had no idea what probenecid was or what it was used for.

Probenecid is a prescription drug for people with gout. It was used to mask steroids back in the 1980’s and 90’s. Dr. Lombardo informed us that he’d only seen this in a player’s system one other time in his 30-year career, so it was perplexing to him. Due to the unusual nature of his test results, Dr. Lombardo delayed submission of results to the NFL to allow us to investigate further. During that time, we looked through Rob’s medical history to make sure he wasn’t given it at a small dose-by a doctor since it’s very difficult to obtain this drug without a prescription. Rob’s legal team was able to obtain records from the pharmacy where Rob gets his seizure medicine filled.

The records showed that they filled a prescription for probenecid prior to filling the prescription for Rob. Probenecid is not commonly filled and it was our belief that Rob’s pills became contaminated.

Clearly many questions existed as to contamination and we were not able to prove them with certainty at the hearing.

Rob tested at levels of 0.17 and 0.34 ng/mL of probenecid in his system. To put that in perspective, if probenecid was used as a masking agent for steroids the dose would have to be between 500-2000 mL. Based upon information provided by our expert, these levels are essentially non-existent and at such a low level they should have been considered a false positive. The level present in Rob’s system was consistent with the level that could be expected from contamination by the pharmacy.. Our expert provided a great analogy here: Imagine a bag of rice with thousands of kernels. The level of probenecid in Rob’s system was equivalent to 1 kernel of rice in a bag among thousands.

Needless to say, the NFL has suspended Rob for 2 games under the Steroid Policy for use of a masking agent. I’ve been working with NFL Players for 20 years, and I can’t think of a situation where I’ve been personally involved where the league was as tone deaf as it was here. Now, Rob will be punished for something that would have been impossible for him to prevent, and even though the NFL admitted during the hearing that it did not believe Rob was intentionally doping, they still suspended him.. The arbitrator gave us a fair hearing, but the strength at which the league argued against Rob was incredibly disappointing.

I was especially disgusted by the actions of NFL Attorney Kevin Manara both prior to and during the hearing. I feel bad for Rob and his family because he did nothing wrong, yet they still had to go through this excruciating process where his character and integrity were ridiculed. I hope the league office will be more thoughtful and conscious in the future if this ever happens to another player.

On Tuesday, Quinn fractured his left hand in practice at training camp and was already expected to miss the rest of the preseason.

Quinn sustained the injury during a one-on-one pass rushing drill against star left tackle Tyron Smith on Tuesday. Executive vice president of personnel Stephen Jones said Quinn was returning to Dallas for surgery, but should be ready for the opener Sept. 8 against the New York Giants.

The Cowboys traded for Quinn in the offseason, signing him to an $8 million, one-year deal while sending a sixth-round pick in next year’s draft to the Dolphins.

Before that, he played for the L.A. Rams.

Robert Quinn #94 of the Los Angeles Rams celebrates a sack during the second quarter of the game against the Miami Dolphins at Los Angeles Coliseum on November 20, 2016 in Los Angeles, California. (Photo by Harry How/Getty Images)

The 29-year-old Quinn has 69 sacks in eight seasons, but his previous double-digit sack season was five years ago.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)