Last season, Devin McCourty's first in the NFL, he had everything to learn about the league, but he knew one thing: opposing quarterbacks would throw in his direction.

Nothing personal, of course, that's just the nature of the position. When you're a young, unproven corner, you get picked on. And teams did just that.

At their peril, it turned out.

By season's end, McCourty was playing – starting – in the Pro Bowl, on the strength of his virtuoso performance as a rookie: seven interceptions (second-most in the league in 2010), 17 passes defensed, two forced fumbles. His pick total is even more impressive when you consider that it ranks second-highest in franchise history for a rookie, behind only Pro Football Hall of Famer Mike Haynes' eight in 1976.

So, when 2011 rolled around and McCourty was elected Patriots a co-captain, he knew better what to expect. As the number-one corner, manning the left flank of New England's secondary, he's be responsible for the opposing team's top receiver, week in and week out, just like last season.

"Last year, I came in as a rookie," he explained last week, "and I was asked the same question, 'Do you think they'll challenge you deep?' I said, 'Yeah,' and they did. This year ... I'm just in my second year ... Teams are going to take their chances."

And so far in 2011, teams like their chances against McCourty and his fellow defensive backs. In the opener at Miami, the group was torched for 416 yards by Chad Henne, 139 of which went directly to 6-4 receiver Brandon Marshall, whom McCourty matched up with throughout the night.

Sunday against the Chargers, Philip Rivers did a number on them, that number being 378. Of those, 172 – nearly half – went to Vincent Jackson, who stands 6-5 and was McCourty's responsibility much of the time. Before he was injured in the first quarter, San Diego's Malcom Floyd, another 6-5 target at wide receiver, was averaging almost 30 yards per catch on just two grabs.

The onus cannot be placed completely on one player, of course, for the problem is more endemic and layered.

"The big problem [against San Diego] was we had our chances to get off the field and we just didn't do a good job of it," Bill Belichick offered Monday after reviewing the game film. His defense allowed the Chargers to convert 10 of their 12 third-down opportunities.

"There were several plays we could have made on third down," the head coach continued, "and I think pretty makeable plays, and we just didn't make them. So, we have to do a better job with our pass rush, with our coverage, with our overall execution of the defense against the passing game than we have in the last two weeks."

On obvious passing downs, New England's nickel package has featured Kyle Arrington as the slot corner, but the 5-9 dynamo who emerged in 2010 as a versatile threat has struggled so far this season.

The Patriots secondary is also getting beaten up, as well as just plain beaten.

Arrington appeared woozy after getting walloped in the head in the game's final minutes. Rookie corner Ras-I Dowling, the tallest Patriot corner at 6-2, was forced to leave the San Diego game in the first half with a thigh injury. He remained on the sideline, in uniform, for the remainder of the contest, but did not return. When Dowling went down, Leigh Bodden was pressed into service, but thumb and back injuries of late have limited his playing time, too.

At the safey spots, Josh Barrett has been sporting the same right hand cast that has suddenly become unfortunately fashionable in the Patriots locker room. Patrick Chung left the Charger game briefly, but returned with one of his own.  

"Yeah, it seems to be going around a little bit in the defensive backs," Barrett said of his unwanted accessory. "You're not in there thinking about it at all, but just wrapping up – small stuff – it can hinder and inhibit you from doing. But you have to play through it. It's part of the game. You know that it's there. Obviously, there's a little bit of pain involved, but guys are out there playing with pain all the time. You have to be as physical as you can with it."

Making matters worse, when they're not getting beaten, they're too often beating themselves.

On two occasions, Bodden was flagged for holding, the penalty for which is five yards and an automatic first down, on plays that would otherwise have been incompletions. In both instances, Bodden's transgression was unnecessary, as the intended receiver wasn't even his man.

"I don't think it's any one specific thing or one particular player or position," Belichick continued. "We just collectively need to do it better."       

Two encouraging signs, though, are 1) that the defense has been able to make big plays when they desperately need them, and the secondary has played a starring role in most of those plays, and 2) the corrections needed appear to be minor in nature.

"We're not out there blowing coverages or anything like that," Barrett observed. "But little things can turn into big things, so, you never want to have little things linger.

"We do need to work on our third down," concluded Barrett, "especially this week."

When the Patriots visit the 2-0 Buffalo Bills, one of the highest scoring teams in the league after two games.