Twenty-three teams wrapped up their three-day rookie camps Sunday. The others held theirs last week.
Until now, football was their pastime; now it's their profession.
NFL teams give their draft picks and college free agents a head start before veterans return Monday for the start of "Phase 3" offseason workouts that feature OTAs, or "Organized Team Activities."
For players, it's their first chance to see what the pros are all about. Coaches get their first look at the new crop of college players their personnel departments have studied for months.
As Denver defensive coordinator Jack Del Rio said, "It's like opening a present at Christmas time."
With draft parties already a hazy memory, rookies arrived at their new jobs for physicals and fittings. They picked their jersey numbers and lockers before gathering for introductions and admonitions about such things as the pitfalls of social media and hangers-on dragging them down.
They toured team headquarters, checked out weight rooms and some even signed their first contracts.
"I was like a little kid. As soon as I put the jersey on, the shorts, the cleats, I wanted to take all types of pictures and send them to my friends," said Broncos running back Montee Ball, who starred at Wisconsin. "But it's all about business."
The actual practices and position drills were what the weekend was mostly about.
"You can't really get ahead of yourself or let the expectations get to you or the pressure get to you," said Kansas City Chiefs tackle Eric Fisher. "It's good being here finally."
For some, such as Manti Te'o, this weekend was all about a fresh start.
"I'm here to play football," Te'o said after practicing for the first time with the San Diego Chargers, determined to push his infamous girlfriend hoax and his lackluster national championship play into the rearview mirror. "I'm not focusing on what is going on on the outside. I'm worried about what we're doing here in San Diego and I'm looking forward to when the veterans come in on Monday."
Whether they were the league's No. 1 overall pick like Fisher or a long shot like Chiefs tight end Demetrius Harris, a basketball star at Wisconsin-Milwaukee, which doesn't even field a football team, they're all in the same boat: NFL novices hoping to prove or disprove personnel people's notions about them.
"I've had to relearn everything," said Harris. "In high school we had basic stuff. This is all new."
To some degree, it's unfamiliar to everyone, even to those who played at big-time college football programs.
"It's been a mental beat down," said Denver Broncos tackle Vinston Painter, a sixth-round draft pick out of Virginia Tech. "But at the same time we just have to stay composed and listen to what Coach is saying and learn from your mistakes every day. There's always something that can be fixed. It's a nice-sized learning curve, but I feel like I'm handling it pretty well."
Going from college to the NFL is akin to jumping from high school to college, only "it's more intensified," said Broncos wide receiver Tavarres King, a fifth-round pick from Georgia. "It's kind of like you have to be perfect out there."
Their every move is monitored in one way or another.
"They're probably a little more under the microscope than maybe they were in their colleges," Broncos coach John Fox said. "You just try to educate them and bring them up to speed as fast as possible. You're going to have some mishaps, you're going to have some bumps.
"The disadvantage they have is that they might be competing against guys that have been doing this for four or five years. So, it's hard to play fast when you're thinking and you don't know what you're doing," Fox said. "So this is a great opportunity, even though it's a short opportunity. We bombard them pretty hard in each meeting."
The weekend was beneficial even to a guy like Lerenetee McCray, a linebacker from Florida who went undrafted after tearing his left rotator cuff last fall and who won't be able to participate in team drills until next month.
"It definitely taught me some of their system, how the coaches operate, how they're going to coach me in some of the stuff that we're going to do once camp comes," McCray said Sunday. "I'm behind the guys who have been practicing and the veterans, but I'm definitely ahead of where I was four days ago."
Coaches appreciate the rookie weekend, too. It's their first chance to see how well their offseason wish lists were fulfilled. Sometimes, they have to, as Fox says, use the reins instead of the spurs to slow down the greenhorns.
"Yeah, a little bit. But it's kind of neat. That's the fun part. They're excited," Fox said. "You know, they've waited their whole lives for this. So, it's a great privilege and really a great accomplishment to have a seat in one of those rooms."
It's also the first chance for coaches to get back outside and do what they do best.
"I think any coach worth their weight likes to be on the grass, and on the field coaching," Fox said. "It's the fun part of coaching. That's really why most of us do it. There's no doubt it's an excitement level, even though it's just the rookies, at this point. To be on the field with them is great."
AP Sports Writers Dave Skretta in Kansas City, Mo., and Bernie Wilson in San Diego contributed to this report.