Wayne Gallman was close to tears.

And this was before he produced 118 yards of offense and scored two touchdowns — one rushing and one receiving — in the Giants’ 24-3 win over the Redskins on Sunday at MetLife Stadium.

Before the game, Gallman, the Giants’ third-year running back who lives in the shadows of Saquon Barkley, could hardly contain his emotions. He was starting in place of the injured Barkley, who’s out for at least a month with a high ankle sprain, and he wanted to make it count.

This was Gallman’s moment. He wanted to embrace it. But he, too, wanted to put his stamp on it, validate his existence and all the hard work he’s put in since the Giants brought him here in 2017.

“I actually almost started to cry because I felt so much emotion,’’ Gallman told The Post in a quiet locker room moment after the game. “I was trying to keep my emotions in, but I wanted to scream before this game started. I’d just been waiting for it, waiting for it and it was finally here and I could just play. I just felt so emotional before the start of the game. I’m just glad I got to do what I did.’’

What Gallman did was rush for 63 yards on 18 carries and catch six passes for 55 yards. His 6-yard touchdown reception in the first quarter gave the Giants a 7-0 lead, and his 1-yard scoring run in the second quarter gave the Giants a 14-0 lead.

“He did a hell of a job,’’ Giants coach Pay Shurmur said. “He stepped in with a heavy load and did a really nice job.’’

One important person in Gallman’s life before the game predicted the success he’d have.

Barkley tweeted: “22 gonna go crazy today,’’ referring to Gallman’s uniform number.

“I don’t know why he does some of the things he does,’’ Gallman said of Barkley with a smile. “He told me that when I was getting taped. He predicted that I’d go off for 150 [yards] today. I’m like, ‘Bro, why would you do that?’ I was like, ‘Now I’ve got to show up.’’’

Gallman did more than merely show up.

“I was here when Wayne was a rookie and he was doing well,’’ Giants center Jon Halapio told The Post. “I was always high on Wayne. Obviously, Saquon is Saquon, but I think people lost vision of who Wayne Gallman was. I never lost confidence in him. I knew what he brought to the table. I knew he was a good back. He can do everything — he can run, he can receive the ball, he’s good on blitz pickup.

“I was excited for his opportunity. He was fired up this whole week knowing he was going to be running back No. 1 and I think he did a good job preparing, practicing hard and he just took advantage of his opportunity.’’

Right guard Kevin Zeitler said Gallman “doesn’t need to be Saquon,’’ adding, “He read the holes, he made plays, he played the game his way. He did great things.’’

“I can’t tell you how many times when I was frustrated and wanted to play more, but it all comes down to team, so you’ve got to throw all those emotions out the door and just prepare like a starter,’’ Gallman said. “And what do you know … Saquon gets hurt and it’s my time. I’ve been waiting for this for a long time and I wasn’t about to let it get away from me.’’

He didn’t.