Cornwell confirmed Tuesday at the NFL owners meetings that he is now representing the agent, Marty Magid, most likely as a preemptive move in the event Magid should face any future litigation or be subject to discipline by the National Football League Players Association.
Cornwell has represented numerous NFL clients in both litigation and grievance procedures.
Dumervil was released by the Broncos shortly before the 4 p.m. ET deadline Friday when his restructured contract that would have reduced his 2013 salary from $12 million to $8 million arrived via fax seven minutes late.
Cornwell produced a time-stamped email Tuesday from Magid to the Broncos' chief negotiator, Mike Sullivan, that notified the team 36 minutes before the deadline that Dumervil was accepting the $4 million pay cut. But as Magid and Sullivan tweaked some rewritten language that pertained to the second year of the contract, time drew uncomfortably tight with the deadline as Dumervil waited at an office in Miami for the document to arrive so he could sign and fax it to the Broncos.
Though Dumervil says he faxed the signed contract ahead of the 4 p.m. ET deadline, it failed to arrive until several minutes later and the Broncos felt compelled to terminate the deal. Consequently, Dumervil is a free agent and the Broncos were forced to take a $4.8 million salary-cap acceleration that has complicated current negotiations between the two sides.
Dumervil fired Magid on Saturday and hired Tom Condon as his new agent, who is talking to at least three teams, including the Broncos and Ravens and reportedly the Steelers.
On Tuesday, Broncos executive vice president of football operations John Elway said the team had extended a new contract offer to Dumervil but did not discuss specifics.
The NFLPA has said it is reviewing the matter.