Before The Gronk, there was The Welk

The sight of tight end Rob Gronkowski getting off a plane wearing a walking boot on his left ankle won't change the outcome of Super Bowl XLVI, but his injury will have an impact.

Although the 2011 season has been dedicated to the development of "The Gronk," Gronkowski's high left ankle sprain will re-educate everyone on the value of "The Welk," Wes Welker. Welker caught 122 passes for 1,569 yards, but his incredible totals were lost in the excitement of Gronkowski and Aaron Hernandez revolutionizing the role of the tight end in a passing offense.

Gronkowski is expected to play, but the ankle injury should minimize his ability to get downfield and possibly allow the Giants to single him. When Gronkowski was in the locker room getting his ankle taped in the AFC Championship Game, a noticeable shift in the pass coverage happened on the field: Jimmy Smith, a tall Baltimore Ravens cornerback, tried to handle Hernandez, and Lardarius Webb stuck to Welker.

Gronkowski is so big and so tough to cover that he often is bracketed with a person dedicated to covering him underneath and another trying to prevent him from going deep. If Gronk can't be Gronk, Welker knows more will fall upon him.

"I know that I need to make some plays with those guys out of the game," Welker said when asked about the impact when one of the tight ends is missing. "They are definitely a big, integral part of our offense and everything that they do. If one of them is not in, you know the other guy has to step up and do some things out there. They have been great players for us all year. We're going to continue to lean on them through this game."

Tom Brady and the Patriots have been leaning heavily on Welker for five years. He has caught 554 passes for 6,105 yards in those five seasons and has allowed the Patriots' offense to reach the extremes of success. The combination of Welker's inside game from the slot to match up with Randy Moss' deep speed gave Brady the edge in a perfect 2007 season until the Patriots lost to the Giants in the Super Bowl.

"The whole Wes Welker thing started when he was in Miami," Patriots coach Bill Belichick said. "He was a very frustrating player to coach against because we really couldn't handle him. He caught passes. He returned kicks. When Olindo Mare got hurt, he even went in and kicked extra points, field goals and kicked off against us. That was annoying, too. We doubled him. We played him in different combinations. He was always the guy we were trying to game plan for, and still couldn't stop him."

Welker was a restricted free agent in 2007, and the Patriots wasted no time trying to get him. Even though the Dolphins were a division rival, they were willing to trade him for second- and seventh-round draft picks. The trade not only came back to burn the Dolphins but also changed offenses.

Using a lot of routes Welker ran when he played for Mike Leach at Texas Tech, the receiver escalated what offenses did from the slot.

"We have just as much trouble covering him in practice, and Tom Brady has just as much confidence throwing to him as the quarterbacks in Miami did when we were trying to defend him," Belichick said. "We don't defend him any better in practice probably than we did trying to defend him when he was at the Dolphins. Nick Saban had him down there, and he just drove us crazy."

Even Welker is amazed how much the slot has evolved over the past couple of seasons. It has become more complicated for defenses, and there's a lot more learning for him.

"It seems like the game changes some as far as passing more and different things like that," Welker said. "I think the slot is an integral part of what today's game is. Understand that if you get stuffed on first down and you are second-and-10 or second-and-9, you are kind of in a position where you need that third receiver to come in and try to make some plays for you and do some different things like that. I think it's changed a little bit."

Welker said that now there are so many more routes and so many more options for him to read while running those routes. What makes him feel better is how healthy he is this season. Welker tore two knee ligaments in 2009, and the recovery slowed him down in 2010. His yards per catch dropped 10.96 to 9.86 last year. His yards after the catch dropped from 5.86 to 4.85. He wasn't the same Welker in 2010.

"I know I wasn't 100 percent because I knew I was capable of so much more," Welker said. "It's just one of those deals where it takes time. I love playing. I wanted to be out there so bad. You push it to the limit of getting back, but, at the same time, you know you are just not the same out there."

His yards after the catch jumped back to 5.8 this year, and Welker is back to being Welker.

"It's been a long recovery from that, but I feel back to my old self," Welker said

For the Patriots to win Super Bowl XLVI, Brady is going to need Welker to be all of his old self if Gronkowski isn't 100 percent.

John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com. Follow Clayton on Twitter