CHARLOTTE, N.C. -- The NFL Players Association is looking into an allegation by Carolina Panthers safety Eric Reid that the NFL is targeting him with excessive drug testing, a league source told ESPN.com.

Reid said on Wednesday that he has been randomly drug tested five times in eight games since taking an initial drug test after he signed with the Panthers in late September.

Reid said he has never failed a drug test to warrant so many tests, all for performance-enhancing drugs, and suggested it was because of his collusion grievance against the NFL.

The grievance was filed in May by the NFLPA on Reid's behalf, alleging that team owners and the league, influenced by President Donald Trump, colluded to prevent Reid's employment because of his protests against social injustice during the national anthem.

Reid, the first player to join former San Francisco 49ers teammate Colin Kaepernick in kneeling during the anthem, continues to pursue the grievance.

"I know what I'm dealing with," Reid said Wednesday. "I have a collusion case against the NFL. This is something that doesn't surprise me from them. It's supposed to be random. It's obviously not. I'm not surprised about it. Even though it seems crazy on the outside looking in, and it is, I'm not surprised."

The NFL declined to comment.

Under the collective bargaining agreement, the NFL and NFLPA are not involved in the testing. It is performed by an independent laboratory, and a computer program selects the names of players to be tested.

"I know I've done nothing wrong, so I'm not concerned that my drug tests will come back ... that I'll fail that test," said Reid, who was last tested after Sunday's home loss to the Seattle Seahawks. "But the system is lying, much like what I'm protesting. It's supposed to be a random system.

"I've been looking at math statistics trying to talk to people. I think it's like a 1 percent chance that somebody gets tested this much. Statistically, big problem."

Reid also has hinted that the league targeted him with a couple of fines for unnecessary roughness penalties. He appealed both and was refunded the $10,026 fine for throwing down Philadelphia Eagles tight end Zach Ertz after his hit on quarterback Carson Wentz.

Ertz, also penalized for unnecessary roughness when he went after Reid following the play, was not fined.

Reid said he has not heard back on his appeal of his $10,026 fine for hitting Pittsburgh Steelers quarterback Ben Roethlisberger, who was hit while sliding at the end of a scramble.

Carolina coach Ron Rivera disagreed with the unnecessary roughness call on that play and sent a video of it into the league for an explanation.

Since there is no appeal for a random drug test, the NFLPA, according to a league source, is looking into what it can do to ensure Reid is being treated fairly.

"I'm not losing any sleep over it, but it should be talked about,'' Reid said. "It's wrong.''