They were ball boys for nearby Santa Margarita High School, led by star quarterback Carson Palmer. At halftime, when the big man on campus was resting, the little Carson wannabes took the field.
Each week, the ball boys and water boys teamed up to face their counterparts in a 10-minute game. They played in one of the end zones -- the long way -- taking it ultra seriously while providing halftime entertainment for the fans.
Who could've guessed that a lasting friendship and, quite possibly, an NFL quarterback-receiver tandem would emerge from that end zone?
"Obviously, it wasn't structured," said McKnight, recalling those "Wonder Years" moments. "It was like, 'Hey, get open.'"
The play calls will be more complex from now on.
The New York Jets used their final selection in last weekend's draft (seventh round, No. 227 overall) on McKnight, a wide receiver from Colorado. Even though they probably have done more pitching and catching over the years than Mariano Rivera and Jorge Posada, this will mark the first time McKnight and Sanchez have played on the same organized team.
They attended different high schools and went their separate ways for college, but they spent school breaks and offseasons working out together at Mission Viejo High School, where Sanchez is hosting about a dozen teammates for a weeklong passing camp.
To McKnight, this seems like old times. The reality hasn't sunk in yet.
"When it really will sink in, if it comes down to it, will be catching my first pass in a game at Meadowlands Stadium or my first touchdown," McKnight said. "That'll be the time when I think, 'OK, this is really cool.' As of right now, it feels the same as it did when we were little kids."
Despite a prolific career at Colorado, where he owns the school record with 215 career receptions, McKnight wasn't considered a lock to be drafted. He's only 5-foot-11, 185 pounds, not unbelievably fast, and some teams assumed he'd wind up signing with the Jets as a free agent because of his relationship with Sanchez.
When the Jets picked him after taking a similarly undersized receiver in the fifth round, Jeremy Kerley, it fueled speculation that Sanchez was behind the pick. They've already heard the whispers around town.
"Everyone around here is like, 'Oh, man, he's getting a handout,'" Sanchez said. "Are you kidding me? I couldn't even talk to people on the team during the lockout. It was just in passing, 'Keep an eye on my boy.'"
McKnight is in a tough and unusual spot. It's not often that you find a seventh-round pick in a pressure situation.
"I understand that it's going to be viewed in that way," he said. "I can't control what people say about me. I can control going out there and working. If the results are there, there's no room for people to speculate judgment on, 'Oh, this guy only got picked because of his friend.'"
If not handled properly by the Jets, it could create awkward moments, especially when it comes time to finalize the 53-man roster. But at the same time, it could have a positive effect on Sanchez, having his buddy around.
In the past, Sanchez has used McKnight as a sounding board, watching film with him and talking through plays and mistakes. McKnight likes to think he's a good listener, and he has benefited, too, improving his knowledge of NFL offenses.
With a devilish grin, Sanchez added, "I'll make it difficult for him."
McKnight has endured his share of difficulties. In 2005, as a senior in high school, he was suspended eight games for writing threatening words to a female English teacher in a creative-writing assignment. The words were haunting and graphic, and the teacher's complaint was leaked to newspapers.
In an interview last weekend with the New York Post, a remorseful McKnight didn't deny anything that was written, but he called it a misunderstanding. He said the class was told the assignment never would be read. The controversy cost McKnight a scholarship to Boise State, but he walked on at Colorado and had a stellar career.
At his Pro Day in March, McKnight caught passes from you-know-who, who flew in from California to serve as his friend's personal quarterback. McKnight's performance was good enough for the Jets, who made the two friends teammates for the first time. Chemistry shouldn't be a problem.
"I'd be lying if I said [our friendship] wasn't beneficial," McKnight said. "We've been out here on this field, throwing, since we were little kids."