FOXBOROUGH, Mass. – Aaron Dobson was probably 9 or 10 when he started following the NFL. Tom Brady was just beginning his reign as the greatest quarterback in New England Patriots history.

“I’ve been watching him for a long time,” said Dobson, now 22.

He’s watching him up close now as one of the 13 rookies on the Patriots’ roster preparing to play the Buffalo Bills in the season opener at 1 p.m. Sunday.

Change is inevitable in the NFL, happens every year as Brady and Coach Bill Belichick have stressed repeatedly throughout the preseason. But the Patriots’ roster has undergone a seismic shift since last year’s final game, the stunning 28-13 loss to the Baltimore Ravens in the AFC championship game at Gillette Stadium.

For various circumstances, four of the top five receivers from last year (Wes Welker, Brandon Lloyd, Aaron Hernandez and Danny Woodhead) are no longer on the roster and the fifth — tight end Rob Gronkowski — is still recovering from multiple offseason surgeries and is listed as doubtful against the Bills.

In their place are four rookies (wide receivers Dobson, Josh Boyce and Kenbrell Thompkins, tight end Zach Sudfeld) and a veteran (Danny Amendola). While the Patriots are expected to run the ball more this year, the development of the passing game will be a crucial piece of the team’s success.

For Brady it’s been a lesson in patience.

“I’m not the most patient guy to be with, so that’s something I’m working on,” he said last week. “But you understand there’s a learning curve and there’s things that are going to come up that look, some guys haven’t experienced the things that I’ve experienced. So you try to talk about it. ‘OK, this is possibly going to happen. If it happens, then I want you to make this adjustment.’ Well, it happens and the adjustment’s not made and I say, ‘Well, I told you ‘

“But sometimes that’s what I do with my 3-year-old (Ben), too. And he doesn’t listen, either.”

Dobson was asked about being compared to a 3-year-old and laughed. “At times I can see how it feels like that to him,” he said. “But it’s all part of the game.”

Brady suggested that he’s invigorated by the challenge this year. He’s spending more time in the film room with the receivers, breaking down each play, each opposing coverage, and telling the youngsters how they should react when certain situations come up.

He’s a perfectionist and is demanding the same of his new receivers.

“He’s like a coach,” said Dobson, a second-round pick. “He knows a lot about the game that I don’t know. He’s been here way longer than me so I’ve got my eyes and ears open.”

Thompkins, an undrafted rookie free agent from Cincinnati, said Brady is all business in the film room.

“He’s just, you know, serious,” said Thompkins. “He’s making sure we’re on top of the things that we need to be on top of.”

Brady makes his points known, quietly in the film room, emphatically on the field. He’s been known to raise his voice occasionally.

“I would say it happens more on the field in the midst of the moment,” said Dobson. “In the film room it’s all about teaching and asking questions.”

This isn’t the first time Brady has had to break in a new crew of receivers. Receivers have come into the Patriots’ system and blossomed with Brady throwing to them. Welker caught 96 passes in two years with Miami before coming to New England. He caught 672 in six years with the Patriots.

David Patten caught 165 passes with 16 touchdowns in four years with the Patriots, 159 with eight touchdowns in eight seasons with four other teams.

David Givens caught 158 passes with 12 touchdowns in 53 games with the Patriots, then left for Tennessee and more money. He played five games for the Titans, tore his ACL and is out of football.

Reche Caldwell is another example. In his one year with Brady, he caught 61 passes with four touchdowns. In four previous years with San Diego, he had a total of 76 catches. He left New England for Washington and had 15 catches in eight games.

Brady has learned to do a lot with a little. But he has some talent in this new group. Amendola is expected to take Welker’s role in the slot and displayed a great feel for what Brady wants him to do in the preseason. If he can stay healthy, he will be a huge addition.

The rookies come in with great potential. Dobson, out of Marshall, has exceptional hands and the size (6-foot-3, 200 pounds) and skill to outfight defensive backs for the high passes.

Boyce, a fourth-round pick out of Texas Christian, has exceptional speed and athleticism. The Patriots likely will use him in a variety of ways.

Thompkins, the undrafted kid, has impressed the most in training camp and seems on the same page with Brady. Perhaps it’s because he feels he has something to prove to everyone who passed him over.

“I try not to get blown away by the whole situation,” he said, asked if he was in awe of anything. “If I start thinking like that, maybe I’ll get overwhelmed. I try to stay level-headed and just keep going. That’s to try not to have any of those wild moments, to just go out and play football.”

Sudfeld, drafted out of Nevada, is expected to start at tight end in Gronkowski’s absence. He’s trying to keep things simple.

“I’m taking it one day at a time and improving on the little things,” he said. “Those are the most important things, the little things.”

Josh McDaniels, the Patriots’ offensive coordinator, likes the versatility they bring to the offense.

“We’ve already moved them and played multiple roles, multiple positions, with them, which in our system is a really big plus,” he said. “They’ve shown that they will study and work at the mental side of the game, to be able to be flexible and play at multiple spots. They are all competitive and they’ve all been productive in different roles throughout the spring and the preseason.”

And they all realize they’re in this together. Asked if there was any rivalry between them, they all said they’re just working together.

“Those are my guys,” said Thompkins. “We just go out there and compete against every other every day. We push each other. We make sure we’re on top of the things that we need to be on top of.”

Thompkins exemplifies the mindset of the three rookie wideouts. They know they’re all fortunate to be with Brady and the Patriots.

“I’m humbled and blessed and grateful to be in this position,” he said. “And I will not take a day for granted.”

Mike Lowe can be contacted at 791-6422 or at:

mlowe@pressherald.com

Twitter: MikeLowePPH