The letter has been delivered.

According to multiple reports Thursday night, the Raiders officially have sent disgruntled defensive lineman Richard Seymour the much-discussed “five-day letter,” which gives Seymour five days to report to Oakland to take his physical.

If the Pro Bowl defensive lineman fails to report for his physical within five days, he could be suspended for the season, which would mean the Raiders would retain his rights in 2010 at his 2009 salary -- roughly $3.7 million -- and he would miss the entire 2009 season. As a result, Seymour, who is also entering the final year of his contract, would not be a free agent following the 2009 season.

Raiders’ radio voice Greg Papa first reported the news at Comcast SportsNet Bay Area, but said he was unsure when the letter was sent. A report from ESPN said the letter was sent out Thursday.

The move would appear to be an effort to spark the Seymour camp into action. A five-time Pro Bowler, Seymour was traded on Sunday by the Patriots to Oakland for a first-round pick in the 2011 draft. However, Seymour has not reported to the Raiders, and the defensive lineman and his agent Eugene Parker have maintained radio silence throughout the process. (Parker did not return an e-mail Thursday night seeking comment.)

On Thursday, Oakland coach Tom Cable declined comment on whether or not Seymour and the Raiders were working on a new contract, but said he had spoken with Seymour and that the player confirmed he wanted to be in Oakland.

The silence from the Seymour camp has been a contrast to the talk between the two organizations, which have taken turns saying Seymour has issues with the franchise that need to be worked out before the trade can go through.

“We have attempted to make a deal,” Cable said earlier in the week when asked about Seymour. “There are some issues still between [Seymour] and the Patriots that are being worked out. Hoping that that will get resolved as quickly as possible. We know that the player wants to be here, but we have really no control over those issues.”

“It’s between [Seymour] and Oakland,” Patriots coach Bill Belichick told WEEI’s “Big Show” on Tuesday afternoon. “We felt organizationally this was a good value for the situation, we know we're giving up something, but we're getting something. We certainly gave up a significant player and we received significant compensation in return”

The NFL has said on a number of occasions that this is a battle between the two teams, and not a league matter. However, the letter now appears to be a clear indication that the Raiders now consider Seymour their property, which would mean the Patriots would get to keep the draft pick, regardless of what Seymour decided to do. Meanwhile, Oakland is left to its own devices to work out a solution.

If Seymour continues to stay away, the Raiders would be within their rights to go after a portion of Seymour's signing bonus from the deal he signed with the Patriots in 2006, a contract that included a bonus of roughly $30 million.