Darius Butler will move into the role of top cornerback. (AP)

It looks like we’ll know if Devin McCourty is truly a four-down player sooner rather than later.

Veteran cornerback Leigh Bodden was placed on season-ending injured reserve Tuesday night with a shoulder problem, ending a frustrating summer for the 28-year-old who struggled to see the field consistently throughout training camp because of knee and shoulder problems — all in the wake of a four-year, $22 million deal he signed with the Patriots in the offseason.

“I’m bummed,” Bodden tweeted shortly after the news was announced, who later added that a torn rotator cuff is what will keep him on the shelf. “I’ve been hitting bumps my whole career and always seem to get past [them]. This will be no different.”

Now, McCourty — along with second-year corner Darius Butler — will be asked to assume a whole lot more responsibility a lot earlier in his career than anticipated. McCourty will move into the starting spot on the left side, with Butler (who tweeted some words of encouragement to Bodden late Tuesday) moving to the right corner spot that was occupied by Bodden last season.

McCourty and Butler have had a chance to play together through a sizable bulk of the preseason. They have started all three games, and received most of the defensive snaps. They have had their ups and downs — against the Saints and Falcons, they both flashed some impressive skills, with McCourty showing a physical side rarely displayed by Patriots’ cornerbacks of the recent past.

While McCourty — described as a “four-down” player by Patriots coach Bill Belichick because of his ability to play defense and contribute on special teams — will be asked to assume a greater part of the game plan in his first year, the move to No. 1 corner will present a new series of challenges for Butler. The Connecticut product will now be asked to defend a premier receiver every week.

But how much of a step down from Bodden will he be? According to Sam Monson of Pro Football Focus, the dropoff isn’t as great as you might initially think. In an e-mail, Monson writes that while Bodden’s numbers were “better across the board than any of the other Patriots corners in [2009], it might surprise some to learn how close Darius Butler was in some areas.”

As evidence, Monson points to the fact that Bodden allowed exactly 50 percent of passes into his coverage to be completed (90 targets, 45 catches), and allowed just 515 yards (11.4 per catch), and was the only corner on the roster not to allow more completions than incompletions. Meanwhile, Butler was thrown at 64 times, and allowed just 36 catches for the next best ratio, and was in the same ballpark with 11.9 yards per catch.

“Where Butler couldn’t match Bodden was in making plays on the ball, which isn’t surprising for a rookie,” Monson wrote. “Bodden batted away 12 passes in addition to the five he picked off, Butler only got his hands to another three passes in addition to the three he picked off.”

When it comes to opposing quarterback rating, the numbers remain the same. According to Monson, opposing quarterbacks had a rating of 59.3 when throwing into Bodden’s coverage, while Butler was next best with a rating of 67.6.

Last season, the trouble really arose once you got past Butler. Quarterbacks who went after Terrence Wheatley had an 86.8 rating (off just 21 snaps and only three balls thrown his way), while Shawn Springs was 94.1 and Jonathan Wilhite was at 115.3. (Wilhite’s numbers were pretty poor — he allowed 65.7 percent of passes thrown his way to be complete, 44 receptions on 67 throws, but those receptions averaged 15 yards per catch, which is not a healthy average. In addition, he was beaten for a touchdown six times to lead the team at corner. Butler was only beaten twice and Bodden four times — but on 240+ more snaps than Wilhite.)

In the end, Monson believes the Patriots shouldn’t suffer a tremendous dropoff going from Bodden to Butler. But if Butler is lost for any significant stretch, well, that’s another matter entirely.

“Darius Butler looks like he has the ability to step up. His coverage numbers were good, and his instincts for playing the ball should improve as he develops,” Monson writes. “But the problem is what happens behind him on the depth chart.”