It has been two weeks since the NFL Players Association filed a collusion complaint against the NFL, claiming a "secret" salary cap was in place during the uncapped 2010 season. On Thursday, the union set about the business of gathering more evidence for its case, submitting requests for documents to the NFL and instructing agents to withhold information related to 2010 contract negotiations, as reported by Pro Football Talk.

The request sent to agents reveals that the NFLPA has already received some evidence from agents. The key passage from the memo reads:

We have spoken with many of you about this claim and your obligation to take all steps to ensure preservation of all documents potentially relevant to the above-captioned matter, and we appreciate the materials received thus far. We write to remind you of your obligation to retain all potentially relevant documents; the term "documents" includes not just hard copy/paper materials, such as all notes taken relating to calls and/or meetings with Club officials, but all electronic communications such as emails and text messages.

On a call with the media on May 23, attorneys for the NFLPA claimed to have "compelling and direct" evidence that the league maintained an unofficial $123 million salary cap in 2010. Additional evidence of a cap that year, according to the union, was revealed in the league's punishment of the Dallas Cowboys and Washington Redskins for violating the cap during the uncapped 2010 season. Both teams appealed the resulting loss of cap dollars, but Special Master Stephen Burbank ruled in favor of the league. The NFLPA filed its collusion case the next day, something the union insists was a coincidence.

The collusion complaint was filed in a Minnesota Federal District Court under Judge David Doty because the NFLPA claims that matter stems from the 1993 Reggie White Settlement. Doty's court has yet to act on the complaint.