Already forced to juggle their secondary almost weekly because of injuries, the New England Patriots now must deal with a wholesale shuffle at linebacker because of the season-ending broken right arm suffered by starter Junior Seau last week.
The upshot of Seau's injury: In New England's "base" 3-4 front, none of the four starting linebackers will be in his normal spot when the Patriots host the Detroit Lions on Sunday afternoon.
"It looks like a lot of moving around, but we've done it before, and these are smart, versatile [linebackers] who can make the adjustments," said fourth-year veteran Tully Banta-Cain, a situational pass-rusher who now moves into the starting lineup. "You just play the basics, not try to do too much, and remember that it's still football, no matter where you're lining up."
For the past seven games, and in nine of their 11 outings, the Patriots, arguably the NFL's best defense at making weekly adjustments to fit the strengths and weaknesses of their opponents, have lined up the same way at linebacker. The starters were Seau and Tedy Bruschi at the inside spots, flanked by Mike Vrabel and Rosevelt Colvin.
The only two games in which that quartet did not start were in the season opener, when Bruschi was hurt, and against Cincinnati on Oct. 1, when the Patriots started a four-man front and a nickel alignment against the Bengals' three-wide receiver formation.
The loss of Seau, who was placed on injured reserve this week, ending his season, has necessitated a game of linebacker musical chairs. Bruschi, who normally starts at the weakside inside spot, now moves to the strongside. Vrabel, who starts at the left outside spot, will switch to the weakside position inside. Colvin will flip from the right outside position to take Vrabel's spot on the left side. And Banta-Cain slides into Colvin's outside spot on the right side.
It's likely that the Patriots will employ more four-man fronts over the final month of the season, to help compensate for the loss of Seau, but the 3-4 scheme remains their staple.
Despite his proven versatility, Vrabel might have the toughest adjustment of the group, and might be the linebacker who makes the biggest sacrifice. Although the 10-year veteran has played inside linebacker in the past -- most notably last season, when Bruschi was still recovering from a stroke and the replacements the Patriots had signed to fill the two inside spots flopped miserably -- he is most effective on the outside, where he makes a lot of big plays.
Still, the key to the wholesale makeover is probably Banta-Cain, who has started just one game in three-plus seasons. The former University of California standout, a seventh-round choice in the 2003 draft, has performed well as a situational player, but now must do so on a full-time basis.
Banta-Cain, 26, has 23 tackles this season and his 3½ sacks are a half-sack more than he registered in his first three seasons combined. It helps that, unlike some teams, the Patriots don't flip their outside linebackers to match the strength of the formation, so Banta-Cain knows he will always be on the right side. He also knows that, in the final year of his contract and eligible for free agency next spring, this represents a big opportunity for him.
"I think I've got enough experience now to handle it, to do things right," he said.
Len Pasquarelli is a senior NFL writer for ESPN.com. To check out Len's chat archive, click here.