It didn’t take long for Brandon Marshall to make his first official play as a Giant.

On the first competitive snap of practice in a seven-on-seven drill on Saturday, Marshall ran a route against Janoris Jenkins down the left side then came back to make an acrobatic grab on a pass from Eli Manning.

“It felt good,” Marshall said. “Being the new guy, you want to prove yourself. Secondly, I want to prove to myself that I can still do it . . . I was like, OK, I can still do this.”

It was one of the highlights of the third day of training camp, the first day in which the offense faced a live defense.

But weeks from now, months from now, there will likely be another play by Marshall that becomes more significant — one that did not result in videos going viral or cheers from the fans in the stands. It was one that fell as an incompletion as Marshall came across the middle and couldn’t quite reach the football thrown out in front of him by Manning.

The catch was the day’s validation. The miss was the day’s lesson.

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“You know, that’s where Eli was supposed to go with the ball and as a receiver, you’ve got to build that chemistry with your quarterback,” Marshall said. “What I did wasn’t wrong if it was a different offense. I throttled in the zone and Eli wants you to run through it. So, it wasn’t like I slowed down but if I burst through that first hole I would’ve caught the ball. Literally, I was like a foot away from making a big play for the team, but I missed it because of that timing.

“Now I got it,” he said, “and I won’t make that mistake again.”

It’s all part of the process of integrating Marshall into a Giants offense that is new to him but has been used by Manning and others in the system for years. It’s all part of Marshall getting to know Manning as much as getting to know the playbook.

That’s why the two spent a good deal of time this offseason on FaceTime going over routes and decisions. But there is only so much that can be accomplished in that way. Some wrinkles need to be ironed out in person. Like the one on Saturday.

“It takes plays like that, right?” Marshall said. “To be really good in the league you can’t make the same mistakes twice. You’ve got to be able to coach and be coached up on the fly. I was able to see it and feel it, and I went to the side and talked to Eli about it a little bit, and now I know when I have that route, I’ll hit it in there a little faster.”

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Marshall did make that first catch, but he was far from the standout receiver in practice. That title went to Odell Beckham Jr. who made a few grabs that brought the fans to their feet . . . and made Marshall grin.

“That’s why I came here, because of him,” Marshall said. “I’m tired of getting double coverage and viced in the red zone. I’ll let him freakin’ carry all the weight.”

Well, not all of the weight. Marshall said he wants to contribute a lot, too. And he expects to.

“As a receiver, that’s what makes us great, but that’s also what holds us back,” Marshall said of having an ego in regards to catches and targets. “It’s definitely about winning, but at the same time, guys want to perform as well. I’ve been there, done that. I’ve had 100 catches several times, done some amazing things, went to some Pro Bowls. The only thing that I haven’t checked off is being able to earn one of those Lombardi trophies.”

Mistake by corrected mistake is the only way to do that.