THIBODAUX — Eli Manning started throwing to Odell Beckham Jr. long before he knew they might someday be a tandem in New York.

Beckham Jr. went to Newman High, the same school where Manning starred. Then, after Beckham made his name at LSU, the receiver started coming down to the Manning Passing Academy in the summer to catch passes from Manning, his brother Peyton and their fleet of college quarterbacks.

But even Manning never expected to see Beckham take the NFL by storm the way the rookie did last fall.

“I knew Odell was a good player; I watched him some at LSU,” Manning said. “Saw him return a punt against Ole Miss — I was rooting against him that time a little bit — but I don’t know. I think he just started making plays in the NFL. The Atlanta game, his first game he kind of came back for, he had a touchdown, and then he started getting more practices, being efficient, running good routes and becoming a smart, savvy receiver at an early age.”

Manning knew Beckham had a chance.

Like any good alum, he’d kept tabs on his old Newman team, and Beckham instantly caught his eye, a little bit like he’d do a couple of years later when Manning flipped on the TV to watch the Southeastern Conference.

Manning liked Beckham enough to make sure he got plenty of chances to test the receiver out as the perfect pitch-and-catch partner once the receiver started making appearances at the Manning Passing Academy.

“I don’t know if he came in high school or not, but when he was at LSU, he’d definitely come and throw a couple of days with us,” Manning said. “A lot of times, twice on Thursdays and then again on Saturdays, he’d come run routes. You know, I knew Odell from, we went to the same high school in Newman, so I’d always kind of team up with him and throw routes with him a lot. Knew him a little bit and knew he was a great talent, so we had a little chemistry before he came to the Giants.”

All of that personal history together gave Manning a little jolt of excitement when the Giants selected Beckham with the 12th pick in the 2014 draft.

Then Beckham hurt his right hamstring.

No matter how much talent Manning knew the rookie had, it’s hard for a first-year player to miss all of training camp, the first four games and integrate seamlessly into an NFL offense, much less turn into one of the league’s most unstoppable weapons.

“I don’t know if I expected all of that, considering he missed so much time,” Manning said.

Beckham surprised everybody.

One of the most acrobatic and devastating receiving options the NFL has seen, Beckham finished with 91 catches for 1,305 yards and 12 touchdowns, earning Rookie of the Year honors.

Beckham became famous for incredible grabs like his leaping, one-handed snag against Dallas on “Sunday Night Football.”

But he also became an all-around threat, capable of taking a short, quick screen from Manning and creating on the move.

And the thing is, Manning thinks Beckham can be even better if he stays healthy for a full season.

“We’ve got to get better chemistry and get on the same page with our timing and find different ways to get him the ball, figure out different ways to get everybody the ball and be more efficient in the offense,” Manning said.

Beckham’s arrival, plus a new scheme installed by offensive coordinator Ben McAdoo, led to one of Manning’s best statistical seasons in 2014. He completed 63.1 percent of his passes for 4,410 yards, 30 touchdowns and 14 interceptions at the age of 33.

Now, as Manning heads into a contract year, he thinks Beckham, a healthy Victor Cruz and LSU product Rueben Randle could make the Giants offense even better.

As long as everybody stays healthy, Manning might have the NFL’s best group of receivers.

“Having Odell in there, healthy for another year, we get Victor Cruz back, Rueben Randle, another LSU guy, so I feel like we’ve got a lot of weapons on offense,” Manning said. “I’ve just got to get them the ball, and we’ll score a lot of points.”