With the arrival of the Cleveland Browns to St. John Fisher College comes the arrival of a familiar face for Bills players, coaches and fans: Browns head coach and former Bills defensive coordinator Mike Pettine. Pettine headed up the Bills defense during the 2013 season. During that season, the Bills allowed the fourth fewest passing yards and the tenth fewest total yards in the league.

"It's great to get back here and just see a lot of familiar faces and some old friends, whether it's players, staff, I know a lot of us were feeling that way," Pettine said. "It's a great setting [for training camp] and I'm glad we could get up here and get some quality work done."

One of the driving forces behind the joint practices is the relationship between Pettine and current Bills head coach Rex Ryan. Their relationship began back in 2005 when both were working for the Baltimore Ravens. When Ryan was hired as the head coach of the New York Jets, Pettine followed him to become their defensive coordinator.

"I didn't realize that this guy shooting video was as smart guy as you could be around," Ryan said of Pettine and his first job with the Ravens. "I'm proud of all the years we spent together and seeing the success that he's had now I'm really proud of that."

"I've worked with him for a long time. A lot of great memories," Pettine said. "He'll be a friend until I take my last breath."

The coaches' relationship goes beyond the football field. The Pettines and the Ryans used to go on vacations in Hawaii together every year. Many people thought that their friendship turned sour after Pettine left the Jets to become the defensive coordinator for the Bills. They both explained, however, that their relationship is as strong as ever.

"People tried to connect the dots there and our relationship hasn't changed. It was good then and it's good now," Pettine said. "We take our shots at each other. Some people interpret that the wrong way."

"Any time you get a new GM it is like, get out," Ryan said in reference to Pettine leaving the Jets. "It was a good time to leave"

"Now, if you've ever been on the headset with us, you'd think that we'll never speak to each other ever again," Pettine joked.

Despite coaching together for so long, Pettine and Ryan have their differences. Although their defensive schemes are similar, in the locker room, they can be two different coaches.

"Rex is more of a laid back type of guy," Bills linebacker Nigel Bradham said. "[Pettine] can be laid back, but if you're not doing your job, then he's going to be on you. They're both great coaches though."

"Rex is a lot louder and more vocal than Pet was," Bills cornerback Aaron Williams said. "Pettine is more soft-spoken. Rex is more vocal, more out there."

According to Bills defensive tackle Kyle Williams, however, the coaches are more similar than they are different and their differences are just highlighted during press conferences.

"I think they would seem different to people that probably aren't in the team rooms with them. But they're a lot more similar than, I think, most people know," he said. "In the team meetings and with the guys they're a lot alike. And obviously defensive schemes are similar. Personality-wise and all that they're a lot alike."

"Their mentality is pretty much similar," Bradham said. "The main thing for them is they want a tough, physical defense; they're both defensive coaches."

Ryan echoed this sentiment, saying that coaching together for so long has naturally led to similar styles.

"We're probably very similar having the same kinds of backgrounds and having been together all those years," he said. "Both our dads are legendary coaches. I would imagine it's similar even to the same slogans and things that we picked up and we all believe in. We're a lot more similar than we are different."

If nothing else, both coaches know how to coach and relate to their players. Both Bradham and Kyle Williams got the chance to catch up with Pettine before practice on Monday and their conversations went beyond the football field.

"He wished me well, he told me I was doing good," Bradham said. "He was happy for me and I appreciated that."

"I talked to him a little bit, you know, kind of caught up," Williams said. "[We] talked about family and just how it's going and that was really it. Really no football, just catching up with one another."

For the Bills and the Browns, Pettine and Ryan's relationship has created an environment where both teams can improve immensely. Both coaches recognize the unique opportunity that their teams have.

"Anytime you can get out and get against another team in a semi-controlled environment, you're going to get more work done than just going against yourselves," Pettine said.

"Both teams came in here trying to get better as a football team and I thought that was really good," Ryan said. "It's great for our defense to go against that offensive line and just good work overall."