He arrived as a fifth-round draft choice in 2003 on the quiet side, and with the typical nervous energy of a rookie and cloaked in the anonymity all offensive linemen selected with the 160th pick can expect. But Diehl was starting at guard by the second preseason game. He has not been out of the lineup since. Today, he is preparing for his ninth season as the Giants' longest-tenured player, a designation he inherited when Rich Seubert was released two weeks ago.
It is a title he wears with honor.
"To be here this long means a lot to me, because this is the organization that believed in me to draft me and bring me here," Diehl said during a training camp break at the Timex Performance Center. "When you look at all the free agent craziness that's going on post-lockout, it makes you appreciate being in the same spot. For me, it's been unbelievable to make this my home. Being drafted out of Illinois and growing up in Chicago, I have all my family there, but this is where I chose to make my home and I spend most of my offseason here and it's an honor for me.
"It also means a lot to be a leader of this team. This year, I'm definitely going to step up and be more vocal. I've always been a guy who led by example but I've been trying to bring the younger guys, the rookies, especially the O-linemen just try to let them see how you work and how things are run around here. The best way to do that is to lead by example. It does mean a lot to me and it's definitely an honor to be wearing the New York Giants helmet and jersey for as long as I have."
Diehl's career has been marked by toughness, consistency, durability and flexibility. He has played every position on the line but center and has started each of the 124 regular season and seven postseason games in which he's played. Diehl started the first 120 regular season games of his career - the longest such streak by a Giant since the introduction of the 16-game schedule in 1978 - before sitting out the first of four consecutive games on Nov. 14, 2010 vs. Dallas. He suffered hamstring and hip injuries the previous week in Seattle. When he did not play the following week vs. Dallas, it ended the streak. Diehl was the only Giant other than Eli Manning to start at least 100 consecutive games since 1978.
During the streak, Diehl started 16 games at right guard as a rookie, 16 at right tackle in 2004, 15 games at left guard and one at right tackle in 2005, 15 games at left guard and one at left tackle in 2006, 16 games at left tackle in 2007, 2008 and 2009 (the year he played in the Pro Bowl) and 10 at left tackle and two at left guard in 2010. This year, Diehl is again a fulltime left guard on the Giants' re-structured line.
No one could have predicted Diehl would give the Giants that kind of productivity when he was a green rookie.
"I was a little wide-eyed," Diehl said. "I don't really think there's any rookie that isn't, but you learn how fast and how quickly everything goes and you're playing up against the best of the best. You're a student of the game in college, but when you're here you need to be in your master's. I had an advantage, because I played in a pro-style offense at Illinois. I could focus on my technique, I could focus on the personnel, because the playbook I already had down. So that was a huge, tremendous advantage for me coming in.
"It was just getting used to playing next to the guys. I constantly told myself in minicamp practices and training camp, 'I'm looking at Kerry Collins, Amani Toomer, Tiki Barber, Jeremy Shockey and just the year before I was watching these guys on T.V.' I kept telling myself that even though I'm a rookie, I can't let these guys down. Football is all about accountability."
But while he was quickly growing as a football player and a professional, Diehl suffered a crushing loss. On Aug. 23, 2003, Diehl started at right guard in the Giants' annual preseason game against the Jets. Immediately after the game, he was summoned to the office of then-coach Jim Fassel, who gave Diehl the stunning and heartbreaking news that his father, Jerry, had died earlier that day of a heart attack.
The hours and days that followed are permanently etched in Diehl's memory. During that difficult time, he was comforted not only by his relatives in Chicago, but by his new family in New Jersey.
"It was tough on me," Diehl said. "That game was on a Saturday. I flew home on Sunday, did all the services on Monday and Tuesday and was back here by Wednesday morning for our Thursday night game with the Ravens. Not only were the guys here counting on me and the team was counting on me, but I know that's what my dad would have wanted. That's the type of guy he was. So I came back and let everybody know that I'm gonna be here each and every Sunday, they know I'm a guy that's gonna be out there fighting and doing everything I can to help our team win.
"When I was in Chicago dealing with that stuff - here I am a rookie that just got drafted - Wellington Mara called and talked to my mom to send his condolences. At the wake there was a huge bouquet of flowers from the New York Giants. When I came back here that Wednesday morning, the first thing I saw was a note in my locker that said the minute I got into the facility, I had to go up and see Wellington. I went up there and I sat in his office. He expressed his condolences and he said, 'I want you to know from here on out that this organization and your teammates, we're your family and we'll always look out for you.' That meant a lot to me and showed a lot to me the type of person that he was. It gave me comfort knowing that I was in the right place. From that point on, like I said before, that's when I treated everybody here like family. This is my family away from Chicago."
Diehl has since been consistent in another aspect of his football life, honoring his father every time he takes the field.
"Every Sunday (assistant equipment manager) Ed Skiba writes "JAD (for Jerry Alan Diehl) on my gloves," Diehl said. "I know that he's there with me in spirit. It's a tribute to him, because if it wasn't for the things he taught me about work ethic and discipline and if you're going to start something or do something, always do it to the best of your ability, I wouldn't be who I am."
Diehl was a quick study on the field, and not just because he was comfortable in the offense. He listened to his coaches and teammates and quickly learned what was necessary to succeed in the NFL.
As a young player, Diehl had mentors. No one helped him more than Seubert, his teammate for eight years.
"Richie was the guard on the other side, he's a Wisconsin guy, I'm from Chicago – it's the Midwest thing," Diehl said. "From day one he really helped me out with different techniques and things to watch. (After his release) I told him I couldn't thank him enough for what he did to help me on the football field and to help me as a player my rookie year. But more importantly he helped me through a tough time in my life when my father had just passed away. I was in a whole new environment and I had no family out here - he really made me feel part of the group, he really brought me in and I can't thank him enough for doing that. If it wasn't for a guy like him to step up or other guys on the team to step up and do that for me, you never know how things would have turned out."
Diehl now practices the selflessness that was extended to him as a young player. In his perfect world, he would play left tackle for the rest of his career. But the Giants need him to play guard, so Diehl moved over without complaint and Will Beatty has stepped in at tackle. While he works to improve his own game, Diehl works with young linemen like Beatty and Mitch Petrus.
"Football is not a game about being an individual, it's about the group and it's about everybody coming together for the best of the team," Diehl said. "Being able to play all the positions and move around is what got me into the NFL and it's gotten me to where I am today. I'm a guy who always puts the team above self and I've always worked hard, regardless of what the situation is. If they need to move me, they're not doing it because I can't get the job done. They're doing it because they believe in me to do it. I'll do whatever. I love being around it and if moving me to guard is gonna help us win football games and give us another opportunity to win a Super Bowl, I'll do it."
Yes, Diehl has certainly grown up with the Giants. And he's not yet finished.
"When I got drafted by the Giants, the furthest East I had been was to play at Penn State," he said. "When I got drafted I landed at Newark and I'm going down the Turnpike and I see all the crates and the landfills and I'm like, 'Oh my gosh, where did I get drafted to?' But I truly love it here and I know that when I'm done playing, I'm gonna stay here for the rest of my life."