The first practice for Buffalo's 2015 draft class and other aspiring NFL players took place late Friday morning at One Bills Drive as rookie minicamp opened under Rex Ryan and his coaching staff. As expected there were lessons to be learned as the young players went through the 90-minute session.

Picking things up

The individual position periods were longer than usual as position coaches began to take on the task of teaching the techniques they'd like to see executed by their players. For a good number of the rookies it was new material.

Third-round pick John Miller was listening closely to offensive line coach Aaron Kromer, who was focused on getting the guard to shoot his hands to quickly make contact with the opposing defensive lineman.

"Yeah, that's one of the small lessons that I'm quickly learning," Miller said. "When I was in college we were taught to tuck our hands, so it's kind of hard trying to break that habit. I want to adapt to what coach is teaching. Get your hands out quick so you can control the guy."

Second-round pick Ron Darby was clearly one of the fastest players on the field, but was getting coached up by secondary coach Donnie Henderson, who was encouraging him to go find the ball on deep routes to make the interception.

"Coach (Henderson) was just telling me once the ball is in the air, don't really worry about the receiver, just look back and play the ball. That's the main thing," said Darby.

"His movement is outstanding," said Ryan of Darby. "He can probably run with anybody in this league so that was no surprise. It looked like he grasped things pretty quickly. I heard that Donnie (Henderson) was already talking to him about his interception points instead of just sticking on a guy. Having a guy that can mentor him will be a big plus for him. He has all the physical tools."

No line play

Once the practice moved to team work the group was limited to 7-on-7 due to the fact that there weren't enough offensive linemen. As an alternative linemen from both sides of the ball had to continue work on the side on their own before observing portions of the team work.

Miller tried to see the silver lining in it.

"We're kind of short on offensive lineman, so the most important thing I tried to take from the day was really learning the coaching techniques, the coaching points," said Miller. "It's good like that because it's kind of slowed down. You kind of get a good feel for what you want to do and what coach wants from you."

O'Leary snaring passes

Bills sixth-round pick TE Nick O'Leary had a good first day. After an early drop early in practice, the tight end did not have another the rest of the way. Among his more impressive grabs was one he made on a pass behind him, reaching back with his left hand without breaking stride across the field during individual work.

During team work O'Leary had a good catch on a well-run route down the seam. He also split a pair of defenders to make another nice play over the middle.

For head coach Rex Ryan it wasn't a surprise.

"We all saw it on tape," said Ryan. "Again he wins the Mackey award, has more receptions and yardage for tight ends than any other guy for two years in a row so clearly we know he can catch the football. He caught one in tight space with two guys on him and another one he was up the seam. One thing we know is if he's around it he's going to catch it."

Another QB

Throwing on Friday was tryout player Austin Trainor. There were a lot of throws he had to make through the course of practice taking every single rep in individual and team. By the end of practice his arm was clearly tiring prompting the Bills to add another tryout quarterback.

"That was pretty obvious," said Ryan. "At the end, he couldn't get out anything. He was dragging."

Buffalo added tryout QB Brandon Lee out of Monmouth late Friday. He's expected to be participating in Saturday's practice.