INDIANAPOLIS -- Frank Reich and Philip Rivers have known each other since at least 2013, when they were with the Chargers. Reich is one of the reasons Rivers decided to sign a one-year, $25 million contract with the Indianapolis Colts in March.

But after the team reported to camp, Rivers was just another player to Reich.

Rivers was working out in the team’s weight room when he saw his new head coach passing through.

“Hey coach,” the quarterback said.

You would think Reich would have spared a minute or two to chat with the player responsible for leading his offense.

Nope, but for a funny reason.

“I just kind of glanced over and waved because someone was walking with me and I was talking with them and because Philip had a mask on,” Reich said. “I didn’t even recognize it was him.”

Rivers gave his coach a pass.

“I kind of hollered and he kept walking and he didn’t know who hollered at him, nor should he,” Rivers said, laughing. “I’m telling you it’s a little bit of a challenge in these masks and things that we are wearing.”

That might be the first and only time that Rivers won't be recognized in the Colts' facility, because he’s already making his presence felt in the locker room, on the practice field and throughout the facility.

“What I have been so impressed with is how much he cares about getting to know his teammates,” tight end Jack Doyle said. “Not just the offensive guys; he is interacting with the defense a ton. If it's playing cornhole in the locker room or things like that -- he just wants to get to know his teammates and wants to be a good teammate. That has been really cool to see and makes a guy fun to play with.”

Rivers has been around long enough to know he can’t come in and force the issue as far as being liked by his new teammates. He’s avoided saying things such as, "This is how I do it." Instead, it’s been more like, "How do we do it here?" Doing that allows him to continue to be himself while also adapting to his new surroundings.

“The biggest thing is, most of it is just me being me,” Rivers said. “I think you certainly don’t want to force it or ever feel like it is fake. I was excited to be here. I was a little nervous the first time in a walk-through, first time in the building like that with all of us here.

“You do want to be yourself and be the guy you’ve always been, but at the same time I think it is also allowing the environment and maybe -- feel out the environment you’re in and feel out what role is needed from you from a standpoint of that, from a leadership standpoint, from a juice standpoint.”

The Colts are in unfamiliar territory of having to get used to a new starting quarterback. That’s because it's basically been Peyton Manning and Andrew Luck since 1998, until Luck retired a year ago this month. The thought was Jacoby Brissett could be the next quarterback in line, but he struggled last season, which is why the 38-year-old Rivers is the starter now.

One thing that was always said about Luck during his seven seasons with the Colts was he “loved” football. That was a favorite saying of the likes of running back Frank Gore and general manager Chris Ballard.

And that’s what’s being said about Rivers already in his short time in Indianapolis.

“Most of the guys I’ve been around here, they all take a very cerebral approach to the game. I think all of the best quarterbacks do that, study and really know what is going on at any moment,” starting left tackle Anthony Castonzo said. “Andrew is the closest I’ve been with that is like a little kid out there, and as old as Philip is, he’s youthful in terms of his energy. ... Being around him in the locker room and hearing him talk and the messages he gives, he’s got that kiddish excitement. I think that is kind of the unique thing that he brings, that he is playing like he is back in middle school playing football.”

Rivers’ excitement comes through most with the offensive line, which could be the best unit he will play behind in his 17-year career. He has a continuing group chat going with his linemen. Castonzo said Rivers left a two-minute voice message talking about how excited he was to be playing with them. That’s not surprising because Rivers isn’t a very mobile quarterback. He's been sacked at least 30 times in nine of the past 10 seasons.

It wasn’t until recently that Rivers was able to get on the field and take snaps from center Ryan Kelly, use his unorthodox motion to throw the ball to wide receiver T.Y. Hilton and hand the ball off to running back Marlon Mack.

“It’s going to be fun, man,” Hilton said. “I can’t wait. He’s special. He’s special in a lot of ways and I just can’t wait. I know one thing about him, that he loves the game of football.”

Another new tweak for Rivers -- outside of wearing a different uniform for the first time in his career -- is a change in the quarterback's diet and workout routine. That falls in line with the "How do we do it here?" that Rivers referred to. It might be hard for some players, especially those who have been in the NFL for a long time, to adapt.

But Rivers has accepted it.

"With it being uncomfortable is an opportunity to grow," Rivers said. "You say, ‘Year 17, you still growing?’ I go, ‘Heck yeah, I hope so. I hope I’m still improving and getting better.’ That is one way from being uncomfortable and then with change, there is just new tweaks. I hate to stretch. I touch my toes one time and throw one football and I am ready to kick it off.

"But there is a time when I’m starting to feel that I need to bear down on that a little bit. So there are some things there that we are doing. It’s those things where -- yeah, I don’t want to go crazy and go, ‘I’m going to be someone totally different than I’ve been.’ I don’t think that would serve well for me or the team. But where are some tweaks where this could be a little bit of an improvement? Maybe it allows you to be stronger in the last quarter of the season.

"The environment is set from the top down and the environment in the locker room -- it is a neat place. I know it is early on and I am still on a high from it being Day 2 or 3 but it’s a great working environment with a lot of great people and I am excited to see what we can get done this year.”