Some were regular-season games in Pop Warner leagues or against archrivals in high school and college. Some were for state championships, bowl games and BCS championships.
But as of now, no game that any of these rookies have participated in will be as important as the preseason game the Eagles will play against the Chicago Bears tomorrow night.
In the grand scheme of the Eagles' 2014 season, the first preseason game isn't that big of a deal.
Even some fans who've been desperate to cure their NFL Jones since January might lose interest after the Eagles starters run the 15 plays or so that coach Chip Kelly has said they will play.
But for an undrafted free agent like Boone, a seventh-round pick like Allen or even a first-round pick like Smith, this is the first chance to make a first impression in an NFL game.
For some of these rookies, there may not be a legitimate opportunity to make a second or third impression if they don't catch an eye right out of the box.
"As you are growing up as a child, this is always a dream," Boone said. "You picture yourself on an NFL team and now that moment could happen.
"But this is just an opportunity to get a chance to do more. You don't want to mess that up because you got caught up in the lights of playing in the NFL.
"Nothing has really changed. It's football. When you get your chance, you have to continue to do what got you to this point. If I go out and do my job, the next thing will take care of itself."
It is a strange situation because while these guys are in an NFL camp and getting paid to play football, each of them knows they are not yet in the NFL.
There is a long way to go between playing tomorrow and surviving all of the cuts to earn a spot on a regular-season roster.
This is for a career now. These players are trying to earn one of the most desirable jobs in America, fighting odds that are incredible.
From all evaluations, Allen has been one of the big surprises of training camp. There is a possibility he could end up taking some snaps with the first-team defense against Chicago.
But Allen is the first to concede that what he has done so far with the Eagles is something that must be continued in actual game action - going at full game speed against an opponent as desperate to make a positive impression as he is.
"Whether you are a high draft pick, low pick or undrafted, you have to be confident," Allen said. "If you are not confident in yourself, there is no way you are going to do well. I think I can play. I think I am good enough.
"I don't want to think about it too hard and psych myself out. It's obviously a big game for me because it is my first game in the NFL and with a new program.
"But I think I'm more excited than anxious or nervous and stuff like that. I just want to get out on the field and play football."
Because of his draft status, Smith is basically guaranteed a spot on the roster, but that doesn't mean he can be in cruise control. High expectations come with being a high pick.
"The veterans have been telling me how NFL play is," Smith said. "I'm curious to see how it plays out.
"It's not a burden, but by being the 26th overall pick, I want to go out there and make plays to show the coaches that they can trust me to be out there."
These guys have been playing football games for a big portion of their lives.
This particular game just happens to be the most important one because it will be their first chance to show what they can do as NFL players . . . well, it's the most important until next Friday when the Birds play their second preseason game at New England and the rookies have to show that their second impression is better than the first.