It was early on in his playing days, back when he still was a scrawny kid in a swampy area of Florida known as “The Muck,” that Janoris Jenkins started to keep notes on wide receivers. During preparations or after a matchup, he’d jot down a few thoughts on each guy, electronically on a tablet or in a notebook.

“You know you’re going to see those guys along the line, whether it’s in college, in a bowl game, the Senior Bowl,” Jenkins said. “You’re always going to see those guys.”

On Monday night, he will again.

The Giants cornerback figures to be locked in on Bengals star receiver A.J. Green in the prime-time game, renewing a rivalry that goes back to when they were just hearing about each other in high school. It followed them through college and the SEC and now finds them going head-to-head for the second time in the NFL.

The Giants have used Jenkins to follow playmakers all year, and there is no reason to think this game will be any different.

That’s just the way Jenkins likes it.

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Asked about drawing the assignment of covering Green, he said: “I would love it. If they give it to me, I wouldn’t mind.”

He said he gets very excited about facing any elite receiver.

“I lick my chops,” he said. “I get happy.”

He’ll have more opportunities to be happy in the coming weeks. After not facing a consensus elite receiver since Dez Bryant in the opener, the Giants (and most likely Jenkins) will face Green, then Alshon Jeffery, Antonio Brown and Bryant again in four of their next five games.

That’s quite a gantlet for the shutdown cornerback who refuses to call himself one.

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“I look at it as going out and doing my job,” he said. “You all look at it as me going out and shutting people down. I look at it as going out and doing my job.”

Jenkins certainly has some happy memories from facing Green. They first met, Jenkins said, at the Under Armour All-America game for high schoolers, though Jenkins said he had heard about Green before that. Three times they went head-to- head in college, with Jenkins playing for Florida and Green for Georgia. Green had 12 catches for 189 yards in those games, but Jenkins remembers the first play of their 2010 matchup. Georgia tried to throw a hitch to Green and Jenkins picked it off.

Last year, with both established in the NFL, they had their first professional confrontation. Jenkins followed Green around for most of it and Green made six catches for 61 yards and a pair of touchdowns.

Jenkins said he was on Green for only one of those scores.

“Blown coverage,” he said.

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Asked if Green ever got the best of him, Jenkins said: “Nah, not for real. He got some plays on me. We both got some plays.”

So what do those notes that the 5-10 Jenkins has been keeping for more than a decade tell him about the 6-4 Green?

“He’s fast, he’s physical,” Jen kins said. “He’s rangy, he’s long. He has a big catch radius and they like to give him the ball.”

Similar to Bryant?

“Not much,” he said. “A.J. is fast and quick, Dez is more physical. Both of them are big guys, but at the end of the day, you have to compete.”

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Jenkins wouldn’t give away all his secrets, though, saying, “Y’all will see on Monday.”

Green has his own book on Jenkins.

“He’s fast, athletic and is very quick,” the Bengals receiver said. “That’s everything you want in a corner.”

He’s been everything the Giants could want, too.