This is the hard truth the Giants face. This is the only way they will get right in the future.

This disaster of a season is not just about a lack of talent. It is not just about injuries.

Plain and simple, this 2-11 season is about the lack of a winning, team-first character. These Giants didn’t work together to get it right.

The Giants have become a selfish, me-first group, and it all started last season when some players, led by Odell Beckham Jr., decided to take a Miami holiday before the playoff game against the Packers — and Ben McAdoo allowed it to happen.

Since that trip they are 2-12, first getting blasted 38-13 in the wild-card game. The new GM and new coach will have to fix all that, most importantly, a new winning attitude must come from within the locker room. That is where true leadership for the future starts.

This is not about the Eli Apple escapades and being inactive on the field but much too active in controversy off the field.

This is about maintaining focus and not being fragile as a team.

As for Beckham, he has not proven worthy of being counted on as a leader. It is more important for him to offer up immature TD celebration material than to truly lead. Yes, Beckham is a hard worker, but there has to be more of a commitment to the team game and a better understanding of the big picture.

There could be hope that a young receiver could take a vocal leadership role. Rookie Evan Engram seems to be the type of player who will not be hesitant to step up in the locker room. He must.

Perhaps his leadership could provide inspiration for Beckham as well.

“Losing is not accepted in this organization,’’ Engram told The Post on Friday. “It is not the standard, no matter what year, what team, it is not going to be tolerated here. It’s been a tough season. But we have stayed together as a team. I’ve definitely learned how hard it is to win in this league. How valuable each play is. It could be a random play in the second quarter, but it could change the outcome of the game.

“Little things lead to so much big things.’’

Do they ever.

“I’ve learned a lot about myself through adversity, I’ve gained a lot,’’ Engram said.

A rookie can’t lead for the most part, but give Engram time to become that vocal leader the Giants desperately need.

“My past teams, my high school team, my college team, I eventually gravitated to that role,’’ Engram said. “For me, though, you have to prove it with actions first.’’

Here is some proof: The rookie tight end leads the Giants in receptions (55), receiving yards (623) and touchdowns (six) as the Giants get set to host the 11-2 Eagles on Sunday.

Interim head coach Steve Spagnuolo said winning is all about getting today’s young athlete to “buy in.’’ He added veterans need to lead the way.

“When a young player can get it from another player, that’s valuable,’’ he said.

Linebacker Jonathan Casillas is on injured reserve with a neck injury. Being a team captain, he knows what leadership is about. He may have played his last game as a Giant, but he is watching closely.

Casillas said a true leader leads off the field in his personal life as well.

A true leader has to perform on the field, and of Engram, Casillas said: “What helps in the locker room is your on-field performance so he has already taken a step in that direction. He has great demeanor. He has great character. I look at him all the time and I am just impressed with the way he comes to work every day. He works really hard.’’

Casillas said Beckham works with the same intensity and in the future, “They are going to have to feed off one another.’’

That would be a start to a better future for the Giants.