Another hit on defense?

Starting FS Brodney Pool didn't practice Monday because of a sprained ankle, presumably hurt Sunday on the practice field. Obviously, Pool won't play Thursday night in Philadelphia -- the starters will rest --but it raises questions about his availability for the season opener. The severity of the injury isn't known.

The Jets already are down two defensive starters, OLB Calvin Pace (broken foot) and CB Darrelle Revis (holdout). They should be in good hands at safety with Eric Smith, one of the most reliable backups on the team.

Pool, a free-agent addition from the Cleveland Browns, still is having growing pains in the Jets' defensive system. On the long pass that was dropped by Redskins WR Santana Moss, the play that looked like CB Antonio Cromartie was beaten, it was actually Pool, according to Rex Ryan. Ryan said he wants Pool to be more aggressive in pass coverage, to be "more of a ballhawk."

Other notes:

• Mark Brunell will start at quarterback in the pre-season finale, followed by Kellen Clemens and Kevin O'Connell. Clemens appears to be on the bubble, but Ryan claimed he has a "pretty strong chance" of making the team.

• The Jets will carry four tight ends on the 53-man roster, according to Ryan -- Dustin Keller, Ben Hartsock, Matt Mulligan and rookie Jeff Cumberland. Ryan admitted it's a "strange deal." You bet it is. The combination of four tight ends and two fullbacks (Tony Richardson and rookie John Conner) is highly unusual.

• RT Damien Woody (lower back) sat out practice and visited a chiropractor. Also out: LB Kenwin Cummings (shoulder), S Don Warren (concussion) and G Charlie Tanner (knee). DE Shaun Ellis (knee) was limited.

• Thursday night's finale in Philly will be a glorified scrimmage. The Jets will play only 36 of their 75 players, and that includes the three specialists. Among those scheduled to play: LG Matt Slauson, OLB/DE Vernon Gholston and WR Santonio Holmes. Holmes, who will leave the team Friday to begin a four-game suspension, should play about three quarters.

• Speaking of Slauson, Ryan still hasn't named him the opening-day starter, and Slauson said he hasn't been told anything, but it's a done deal. Just like we told you a week ago.

• Ryan doesn't agree with those who believe Cromartie had a shaky game against the Redskins. Ryan said Cromartie played well, claiming one of the two penalties on him was a bad call.

• Ryan on the Jets' Big Four additions, LaDainian Tomlinson, Cromartie, Holmes and Jason Taylor (and Pool, if you make it five): "We struck gold on a few of them ... and we get to showcase that when we start the season." Well, except for Holmes, who will be suspended.

UPDATE: Pool was injured during the game, but the team didn't reveal the injury until Monday, when reporters were allowed at practice.