Bill Belichick is ranked as the best coach in the NFL, according to a poll of 30 league insiders.

Pete Carroll and Sean Payton are ranked second and third and are also in their first tier.

"The most important thing to me is the ability to control the offense, the defense and the special teams," a GM said in describing the ideal coach. "You can change and you can coach multiple things and you have the ability to teach almost every position group. Then you can lose any coach you want and replace from within because the head coach is the talent. Belichick is the ultimate model of that."

Belichick commmanded a 1 vote on 28 of 30 ballots.

In Tier 2 are Andy Reid at No. 4, Tom Coughlin at No. 5, Mike McCarthy and Mike Tomlin at No. 6, Jim Harbaugh at No. 8, John Harbaugh at No. 9, John Fox at No. 10 , Jeff Fisher at No. 11, Chip Kelly at No. 12, Bruce Arians at No. 13, Lovie Smith at No. 14 and Mavin Lewis at No. 15.

Tier 3 is led by Chuck Pagano At No. 16, followed by Rex Ryan (17), Mike Smith (18), Gus Bradley (19), Ken Whisenhunt (20), Mike McCoy (20), Marc Trestman (22) and Ron Rivera (23).

Tier 4 features Mike Zimmer (24), Jay Gruden (25), Bill O'Brien (26), Jim Caldwell (27), Doug Marrone (28), Joe Philbin (29), Jason Garrett (30), Mike Pettine (31) and Bruce Allen (32).

Wes Welker suffered a concussion on a hit to the helmet from D.J. Swearinger.

Welker missed three games last season after sustaining two concussions.

"It was determined it was a concussion," John Fox said. "He'll go through the protocol. The biggest thing on him is, of course, player safety. He'll go through the protocol."

In terms of a timetable for Welker's return, Fox said that will be determined by doctors.

"We'll leave that to the medical people and he won't come back until he's ready to come back," the coach said.

Danny Trevathan has a fracture just below his left knee joint and will miss six to eight weeks, the team announced Tuesday.

The third-year linebacker, who led the Denver Broncos with 124 tackles last season, is one of the most important players in defensive coordinator Jack Del Rio's scheme.

Trevathan, who had an MRI after he was carted off the field during Tuesday morning's practice, suffered a medial tibial impaction fracture. He will not undergo surgery.

"They told me that my ACL and MCL are fine, but that I have a fracture in my knee," Trevathan told ESPN's Josina Anderson. "The doctor told me I was going to be out four to eight weeks, but I told him four to six. I'm not tripping. I will bounce back. I'm a soldier."

Brock Osweiler is ready to make the most of his preseason snaps with Peyton Manning unlikely to play much.

"I’m excited to go out there and see what I can do," Osweiler said. "You always want to compete, we all signed up to play. That’s what I want to do." 

Osweiler was a second round pick in 2012 and is being groomed to take over for Manning whenever the future Hall of Famer retires.

"It’s always a little faster," Osweiler said. "It’s always a little bit different. But that’s one of those things you have to understand. 'Hey, I’m in there with the first group right now, they play a certain way.' And you just need to acclimate to that and adjust and keep the sticks rolling ... There’s no other team I’d rather play, first preseason game. Like I said before, they’re the world champs and they’re the world champs for a reason. I expect their best effort. They have a very talented defense that flies around and gets after it. So I think it’ll be a great challenge for us, but I’m excited for that challenge and I think it’ll be a lot of fun." 

Osweiler was the youngest quarterback on the draft board in ’12 and won’t turn 24 until November. He says Year 3 already feels a bit different than his first two. 

"Absolutely, Year 1, it’s almost like the goal is just learning the playbook, and then Year 2 is apply it to the field, eliminate those mistakes you were making in Year 1," Osweiler said. “And same thing goes from Year 2 to Year 3. So from the way practices have gone from the start of training camp, and even back to OTAs, I feel like a completely different quarterback. I feel like I’m playing at a much higher level than I did last year, and especially my rookie year. I have very high goals for myself and very high expectations, and I expect to play well Thursday."