Source: Injured Warren week to week

FOXBOROUGH - Defensive end Ty Warren missed his second straight practice yesterday because of a groin injury, an indication he could miss his second straight game - and third in four weeks.

However, an NFL source said Warren probably won't go on injured reserve. The source said Warren's availability is a "week-to-week thing" and the team is trying to manage the injury so Warren can play again this season.

An ESPN report Wednesday said Warren's injury could keep him out "a while."

When asked about that characterization, the source said, "I think that's strong." The Patriots travel to Seattle to play the Seahawks Sunday, then play at Oakland Dec. 14.

Warren sat out with the groin injury in a 34-31 overtime loss to the Jets Nov. 13. He returned for the Patriots' 48-28 win over the Dolphins the next week, finishing with three tackles, but said that he couldn't play at his usual level.

The Patriots elected to sit Warren last Sunday in a 33-10 loss to the Steelers, replacing him at left defensive end with Mike Wright. That game was played in slick, rainy conditions. The source said Warren had not aggravated the injury since he played against Miami.

In the last two games without Warren, the Patriots allowed 140 yards rushing on 39 carries to the Jets and 161 yards rushing on 34 carries to the Steelers.

Slater recovering

Matthew Slater felt awful Sunday night, replaying his fumble on a kickoff return over and over in his head. By Wednesday afternoon, Slater had pushed the play out of his mind. The first step was receiving a call Sunday night from his father, Hall of Fame offensive tackle Jackie Slater.

"I had a conversation with my dad about times he gave up three or four sacks in a game," Slater said. "I said, 'Well, if he had days like that, then everybody has to have to some of them.' You have to have a short memory playing this game. He told me what Walter Payton once said: 'You've got to have amnesia.' You've got to realize those types of things happen to even the best of players."

Slater remains in the kickoff return rotation with primary returner Ellis Hobbs, he said. Slater never experienced a botched kickoff return in college like he did last Sunday against the Steelers. The ball bounced off his chest and arms and fell to the ground. When he tried to grab the ball, he kicked it away, then chased it. One Steeler shoved him out of the way, and another pounced on the ball. The mistake sparked the Patriots' unraveling in a 33-10 loss.

"I'm very competitive, and I take pride in doing my job and doing it well," Slater said. "And I didn't do that on Sunday. It was very tough."

During practice Wednesday, catching kickoffs felt cleansing for Slater. It helped, too, that teammates and coaches offered encouragement.

"You've got to put it behind you," Slater said. "You can't continue to dwell on it. As far as I'm concerned, we've got Seattle this week. I've got to do what they're asking me to do and prepare to do my job this week. I can't continue to think about that play, because it will affect me negatively if I do."

Loud practice

The Patriots will play for the first time in Seattle's Qwest Field, a stadium designed with the intention of making crowd noise as loud as possible, with metal bleachers and a roof constructed to direct noise toward the field. The extra noise can be jarring - opponents have been called for 77 false starts at Qwest Field since 2005, the most of any stadium in the NFL during that span.

The Patriots practice using artificial noise to prepare their offense before a road game. This week, the Patriots have been blaring rock music during practice.

"Talking to other coaches and teams that have [played in Seattle], it's definitely an issue," coach Bill Belichick said. "So we'll crank up the noise and make sure we have some experience with not being able to hear. We'll have to have really good concentration and do our communication either visually or sometimes signaling. That'll be a challenge for us."

It will be a challenge for quarterback Matt Cassel, who did not experience playing in rabid college environments. He has gone 3-2 in five road games this season, the loudest of which, he said, was his first start, against the Jets in Giants Stadium. Sunday's volume should surpass that.

"We have to use a different message of cadence," Cassel said. "You have to be sure to communicate what we are trying to get done in the huddle, be loud, and if there are any questions, ask before we break that huddle because we know that can be tough at times."

It's settled

The Patriots and cornerback Jason Webster reached an injury settlement, making Webster a free agent. Webster, who played in three games this season, was placed on injured reserve Tuesday with an ankle injury . . . For the second straight day, Pierre Woods (jaw), Adalius Thomas (forearm), Kelley Washington (thigh), and Vince Redd (ankle) also did not practice . . . Defensive lineman and Georgia alum Richard Seymour continued to wear a Georgia Tech football T-shirt yesterday as penance for his bet with rookie Gary Guyton, a Georgia Tech alum, as a result of Georgia Tech's 45-42 victory over Georgia last Saturday. Cassel, a Southern Cal grad, and Slater, from UCLA, have a similar wager on tomorrow's Trojans-Bruins game. "Of course we do," Cassel said. "I am going to be giving a lot of points, I'm sure."

Mike Reiss of the Globe staff contributed to this report.