FOXBOROUGH, Mass. -- For those who believe football games are won on the line of scrimmage, the New England Patriots' 2010 training camp hasn't gone as smoothly as hoped.
Between the contract standoff with left guard Logan Mankins and the injuries of guard/tackle Nick Kaczur and defensive end Ty Warren, the Patriots currently are operating without three mainstays on the line. They are players who consistently do the dirty work, the stuff that's easy to overlook until it's gone.
Without them on the field, there are wider-than-desired cracks in the foundation the Patriots are trying to build.
Warren is the most recent concern, the potential severity of his situation coming to light from, of all people, coach Bill Belichick.
Usually not one to reveal injury details, Belichick said Warren's injury -- reportedly a hip problem -- needs further evaluation. Belichick put the team's other injured players in the day-to-day category, so his comments on Warren, who has missed the past 12 full-pads practices, made it seem the team fears something serious. Belichick put Kaczur, who has told teammates that he has a significant back injury that could threaten his 2010 season, into a similar category as Warren.
"We'll just have to wait until we get a little more information there," Belichick said.
Warren's absence highlights the team's depth concerns on the defensive line. His top backup in spring camps was 2009 second-round draft choice Ron Brace, but Brace opened training camp on the non-football injury list and has yet to practice. He has been one of the team's bigger disappointments of camp.
So while the Patriots opened camp with a big question regarding who would start at right defensive end, a position that was steamrolled in the playoff loss to the Baltimore Ravens, now they are looking to plug holes at both ends. Not a good situation.
This is Gerard Warren's first year in the Patriots' system, and thus he's still learning the tricks of the trade. Meanwhile, Wright seems a lot like the player he replaced, Jarvis Green -- a solid option off the bench or in spot duty, but one who could wear down if counted on over a 16-game schedule.
Damione Lewis, a 10-year veteran, is a top backup, and a bit farther down the depth chart are Darryl Richard (second year) and rookies Kade Weston (seventh round) and Brandon Deaderick (seventh round).
The 32-year-old Lewis, like Gerard Warren, is in his first year in the Patriots' system. Having played solely in 4-3 defenses over his career, he's had to reinvent himself from pure penetrator to someone who holds the point of attack.
"I think it's a bit more physical than a 4-3, which is about exploding and getting up field and causing penetration and trying to disrupt from that standpoint," he said. "Here, you are actually honoring and playing blocks, trying to sit and then make the tackle. I think that's the biggest difference: the pace of the game."
That's one of the main aspects of the Patriots' defense that has made a mark on Lewis -- how physical linemen have to be against the run.
Just as the defense is a physical unit up front, so too is the Patriots' offensive front. One of the goals for the offensive line was to become even more physical in 2010, but it's not a promising sign when the team is bringing in the likes of Eric Ghiaciuc and Darnell Stapleton -- who did not play in 2009 -- this early in camp. That reflects how thin the numbers are on the interior of the line.
They are thin on the defensive edge, too, with Ty Warren's injury the latest concern.
Between Mankins, Warren and Kaczur, the Patriots have generally received consistent power and toughness over the years. Their play might not catch the eye as obviously as a skill-position player such as Randy Moss, but it's the foundation-type stuff that good teams are built upon.
This is where the Patriots have taken their most significant hits through the first 10 days of training camp.
Mike Reiss covers the Patriots for ESPNBoston.com. Follow him on Twitter.