FOXBORO — The Patriots ended the 2010 season with just eight healthy defensive linemen. Now, they have almost three times that many in training camp.

The acquisitions of both Shaun Ellis and Andre Carter, as well as the return of Gerard Warren, were made official on Monday, brining the total number of defensive lineman on New England’s current roster to 21.

“It’s a big group,” acknowledged Patriots coach Bill Belichick on Monday.

In contrast to where they were at the end of the 2010 season, the Patriots now have bodies to spare up front. There are 12 players who could be classified as defensive tackles: Warren, Vince Wilfork, Albert Haynesworth, Mike Wright, Myron Pryor, Kyle Love, Kade Weston, Steve Williams, Ron Brace, Brandon Deaderick, Landon Cohen and Darryl Richard.

In addition, there are nine players who could be labeled defensive ends: Ellis, Mark Anderson, Andre Carter, Markell Cater, Jermaine Cunningham (who could really be classified as a linebacker or defensive end because of his positional versatility based on what we've seen so far in camp), Aaron Lavarlas, Eric Moore, Clay Nurse and Alex Silvestro.

“We’re trying to always add as many good players are we can to the team,” Belichick said on Monday. “The best ones will play and the ones that don’t play as well will play a little bit less. That’s just competition. We’re always looking for competition at every position, and I think we have good competition on this team.”

What does it all mean? Belichick has never been the type to try and wedge a square peg into a round hole — that is to say, he has always been good at maximizing a players’ strengths. So when you look at Monday’s acquisitions of Ellis and Carter (as well as the deals that brought Haynesworth and Anderson to town before them) and you consider where they’ve excelled over the course of their careers, it certainly makes it look like the Patriots are going to be spending more time in four-man fronts this season.

That doesn’t mean that New England should strictly be characterized as a 4-3 team, however. The Patriots have always shown a willingness to adapt and evolve on defense based on personnel and opponent, and Belichick said on Monday that approach would not be altered.

“I don’t think our defensive philosophy is going to change,” Belichick said. “I think how we align and how we handle the responsibilities, I think that could definitely change by game plan or by what we feel are our strengths and weaknesses and how to best deploy the players. [But] I don’t think fundamentally our philosophy and our techniques are going to change.

“I think what we’re teaching we’re going to continue to teach and use on a very consistent basis. How, strategically, we want to move guys around and put them in certain alignments or how to configure them relative to certain to formations and tie it in with coverages and things like that — I think there’s flexibility there.”

In addition to veterans of the New England system like Wilfork and Wright who have shown some versatility and have a familiarity with the system, one of the newcomers who is probably going to provide some of that flexibility that Belichick talked about Monday is Ellis. He has experience in both three-man and four-man fronts from his time with the Jets as a defensive end, and while he acknowledged he’s most comfortable in the 4-3, he said he’s down for whatever.

“I’ve played all of them,” he said when asked which system better fits his abilities. “So to me it doesn’t matter. I feel like I can play all positions — I line up in all positions, so I’ve been doing it my whole career. It’s natural.”

That flexibility might not come so naturally for Carter. Along with Haynesworth, he publicly expressed his distaste for playing in a 3-4 system while with the Redskins, a point reiterated Monday by Belichick.

“It was a great scheme, but just being the person I am, I’ve just been a defensive end,” Carter said. “The 3-4 did create versatility in me, and I did my due diligence. It’s a thing of the past, and I just have to move on.”

However, the Patriots’ coach seemed to indicate that Carter wouldn’t have to worry too much about playing much 3-4, at least during his time in New England.

“Last year, when Washington went to the 3-4 defense, it wasn’t a good fit for him evidently in that system,” Belichick said of Carter. “But we feel like with what we’ll be asking him to do this year — relative to what he was asked to do last year, what we’ve seen him do in the first nine years of his career — that we can use his ability on the edge and he can be effective.”

Once the cuts start coming down, there’s no way the Patriots are going to keep 21 defensive linemen on the final 53-man roster. Based on what we’ve seen in camp thus far and what Belichick has said, New England will likely keep a couple of specialists (like Anderson and Carter as pass-rushing ends for a possible four-man front, as well as Haynesworth as a defensive tackle and run-stopper in 4-3), as well as others who have shown a versatility to bounce back and forth between the two (namely, players like Wilfork, Wright and Ellis).

“Depending on how our team shakes up [and] what our players can do — some of these players I’ve never coached before so I’m not sure exactly how they’ll fit in or what exact roles they’ll be able to play in this defense,” Belichick said. “I just have to wait and see how that turns out. I think we’ll have enough defense and be able to do things to put players in a position where they can be productive.”