"I think it's a great selection by the team," Belichick said at his morning press conference. "These four guys have all been in that role before and have done all the things that you would want your captains to do. I think we have a lot of other good leadership on the team ... but I think those four they do a great job. They were selected by the team."
None of the players are primary contributors on special teams. Receiver Sam Aiken, whose primary contributions came on special teams, was a captain last year.
Asked about the special teams void, Belichick said the "four team captains represent everybody."
On a related note, Patriots receiver Randy Moss had been a captain the last two years and is not a captain this season.