FOXBOROUGH, Mass. -- Despite their offensive dominance through the first two weeks of the season, the New England Patriots have concerns. Third-down defense and pass coverage are chief among them, but maybe nothing is more troublesome at the moment than injuries.
The Patriots placed center Dan Koppen and defensive tackle Myron Pryor on injured reserve Wednesday, ending their seasons. In addition, the team signed cornerback Phillip Adams and defensive lineman Landon Cohen to take their spots on the 53-man roster.
Additionally, safety Patrick Chung had surgery on his right thumb this week after injuring it in Sunday's win over the San Diego Chargers, according to sources. The surgery puts Chung's status for Sunday's game at Buffalo in question.
In Sunday's game, the Patriots watched at least eight players exit with injuries.
What's more, New England's first injury report of the week included 15 names, a whopping 28.3 percent of the 53-man roster. While only five players were held out of Wednesday's session, seven others were limited, a fairly alarming number when you consider the Buffalo Bills had seven players total on their injury report (one of whom had full participation Wednesday).
Patriots coach Bill Belichick noted during his news conference Wednesday that a team typically utilizes about 60 players per year, many of whom join the team through practice squad promotions. But New England has already reached outside its organization for seven players (OL Brian Waters, TE Dan Gronkowski, LS Danny Aiken, LB A.J. Edds, OL Donald Thomas, Adams and Cohen) since setting its initial 53-man roster on Sept. 3, in addition to signing offensive lineman Thomas Welch from the practice squad before the opening game in Miami.
The position of greatest concern at the moment is cornerback. Kyle Arrington, whose duties extend to special teams, suffered a concussion in Sunday's win over the Chargers and did not practice Wednesday. Rookie Ras-I Dowling, the other starter opposite second-year man Devin McCourty, left Sunday's game with a hip injury late in the first half and remained limited Wednesday. Leigh Bodden is still working his way back after missing all of last season and remains on the injury report with a hand injury (though he participated fully Wednesday).
Before Wednesday's addition of Adams, Antwaun Molden was the only other available corner. After being signed late in the preseason, Molden made enough of an impression to stick on the 53-man roster but he has played only 32 defensive snaps over three seasons with the Houston Texans, according to the analytical site Pro Football Focus.
Adams, a seventh-round pick of the San Francisco 49ers last year, doesn't have much more experience. He played only 76 defensive snaps in eight games at cornerback during his rookie campaign.
The health of New England's secondary as a whole is a concern. Chung -- the glue of an overhauled safety unit that jettisoned Brandon Meriweather and James Sanders before the start of the season -- was able to return to Sunday's game with a hard cast on, but did not practice Wednesday. Fellow safety Josh Barrett is nursing a thumb injury of his own (though he participated fully on Wednesday).
For a Patriots team that has allowed 381 passing yards per game over the first two weeks of the season, the lack of depth has to be troubling as teams are likely to try to exploit that area.
But the Patriots' problems are not limited to the secondary, as Wednesday's moves illustrated.
A defensive line that got beefed up during the offseason has already lost Pryor and Mike Wright, whose future remains uncertain after he suffered a concussion in Week 1. Wright missed the final seven games last season because of a concussion, and the team seems to be in wait-and-see mode.
"I talked to Mike about it and Mike has obviously talked to our medical people," Belichick said. "I think there's a good understanding of what the situation is and how it changes or when it changes, this year relative to last year to other years, those are medical decisions."
The Patriots seemingly had two options on speed dial in Cohen and Gerard Warren, the veteran who Belichick said earlier this month could be brought back after being cut before Week 1. As more of an interior pass-rusher, Cohen made more sense for now and will add depth behind the likes of Vince Wilfork, Kyle Love and Albert Haynesworth.
Cohen, who played in the final three games of the 2010 season for New England, could be thrust right back into the mix.
"I'm happy to be here, happy for the opportunity, and ready to get in the game plan for Buffalo," said Cohen.
Others aren't so fortunate.
Pryor, who missed the final seven games of last season due to injury, hurt his shoulder in the first half Sunday.
Koppen fractured his left ankle late in the first half of New England's season-opening win in Miami. Initial reports suggested Koppen might be able to return later in the season, but with injuries already mounting and Dan Connolly appearing steady in Koppen's place in Week 2, the team apparently wasn't willing to hold up a roster spot while waiting to see if Koppen could return.
The question is whether there's enough depth on the offensive line to survive more injuries over the next 14 weeks. The Patriots played Week 1 without Sebastian Vollmer, forcing rookie Nate Solder into the fire. Vollmer returned against San Diego, but sat out Wednesday's practice.
A good chunk of the Patriots' eight-man practice squad is comprised of offensive linemen (tackles Matt Kopa and Welch, and guard Nick McDonald). As Belichick pointed out, there's a decent chance those players could end up as part of the 53-man roster at some point.
Amidst it all, there's lingering concern about tight end Aaron Hernandez, who is expected to miss game action after taking a helmet to the knee late in Sunday's win.
In the end, injuries are part of the game. It's something the Patriots will deal with throughout the season. They've caught a rash of them early on and it will test their depth early in the 2011 campaign.
Chris Forsberg covers the Patriots for ESPNBoston.com.