FOXBORO — It has been the most eventful year of Wes Welker’s professional life.

The wide receiver ripped up his left knee on the turf at Reliant Stadium in January, and left the field in tears with a blown out ACL and MCL. After an offseason of rehab, he stunned everyone by making it back in time for training camp, and was on the field for the regular season opener against the Bengals.

While Welker started the 2010 season relatively strong — in four of his first five games, he had at least six catches, including an eight-catch, 70-yard performance against the Dolphins in Miami — his numbers have decreased recently. Over the last three games, he’s had 11 total receptions, with the low point being a three-catch outing in a win over Minnesota on Oct. 31.

While he still leads the Patriots with 44 catches, it’s below his usual output over an eight-game stretch with New England. (By way of comparison, he had 79 catches after eight games in 2009 — the best half-season of his career — but 49 catches in 2008 and 56 in 2007 in that same period.)

Part of that can be attributed to the reshaping of the New England offense in the wake of the Randy Moss trade. But are there other factors at play? Welker has said several times that he hates the brace he’s been wearing, and the last two weeks, Welker has gone with a thinner brace on the knee, and told reporters before the Cleveland game that he’s continuing to progress.

But frankly, his astoundingly quick rehab may have caused all of us to expect too much of Welker in his first year back after suffering the sort of injury it’s taken others a year to fully recover from. Welker has been quick to remind people since the start of training camp that he doesn’t feel completely confident in his knee, and noted sports injury expert Will Carroll believes there’s something to the idea.

“It’s a reasonable assumption — the normal pattern is they come back, but lack confidence in the knee,” Carroll said of similar athletes who have gone through what Welker endured.

In his latest column, Carroll writes about players who have suffered similar injuries reflexively “guarding” the knee in the early stages of their comeback, and brings up an instance involving running back Deuce McAllister. In one of his first games back, McAllister made a hard cut on a touchdown run, and looked down at his knee when he reached the end zone. The cut helped McAllister realize that he was all the way back.

“You'll hear players say, ‘It just doesn't feel right,’ even when all the measurables are there,” Carroll said. “To think he's had a mild setback or experienced something that cost him some confidence isn’t outrageous.”

As for the on-field production, it’s important to remember that aside from the star-crossed 2007 season, his overall receptions for a half-season aren’t that dramatically different. (His catches per game — 7.2 — since 2007 remains best in football.) However, his yards after catch, an area where he has traditionally dominated, had decreased. Welker, who has more YAC than anyone in football since the start of the 2007 season (2,320), isn’t even in the Top 20 this year.

A closer look at the half-year numbers reveals that Welker could be headed for a unique statistical season, the kind of year that has only happened to a handful of players — all of them running backs — according to Mike Tanier of Football Outsiders.

“No wide receiver has ever had a season like Welker is destined for: 88 catches at 8.1 yards per catch,” Tanier said. “All of the historic similarities are running backs.”

Player            Year           Catches         Yds.        Avg

Larry Centers         1995        101        962        9.5

Larry Centers         1996        99        766        7.7

Larry Centers         2000        81        600        7.9

Larry Centers         2001        80        620        7.8

Brian Westbrook    2007        90        771        8.6

Rickey Young    1978        88        704        8.0

Richie Anderson    2000        88        953        9.7

Derek Loville    1995        87        662        7.6

Earl Cooper        1980        83        567        6.8

Ted Brown        1981        83        694        8.4

Joe Washington    1979        82        750        9.1

Tanier (who has more on the topic here) says the only wide receivers with more than 80 catches and a yards-per-catch average of less than 10 were T.J. Houshmandzadeh in 2007 and Troy Brown in 2002.

“Both were coming off 100-catch seasons, like Welker,” Tanier said. “What I think happened was that, a) the coach and/or QB got carried away throwing screens and 5-yard ‘smash’ routes; b) defenses started allowing the catch and making the tackle right away; and c) the receivers all lost a half-step. When you are trying to make a living off yards after catch, the half-step makes a difference.”

Tanier believes that Welker’s career arc could mirror that of Brown, who went from 101 catches for 1,199 yards and an average of 11.9 yards per catch to 97-890-9.2 the following season to 40-472-11.8 in 2003. However, Brown was still able to make great contributions as a punt returner — he registered a combined 468 yards as a punt returner in 2002 and 2003, and had an average of 10.1 yards per return in 2003.

“Brown is an interesting comparison,” Tanier said. “I have a feeling Welker will soon go back to life as a 50-catch slot guy, return man … and emergency kicker.”