John Mara said the Giants have “lost some credibility as an organization” after three straight losing seasons and four in a row without reaching the playoffs. But he is keeping his faith in the guy who, in large part, put the franchise in the mess it currently finds itself.

“Jerry knows this is on him,” Mara said of general manager Jerry Reese, who is keeping his job while the head coach walks away without much of a fight from the organization to dissuade him. “I’ve had that discussion [with Reese]. You can’t hide from the record. It’s up to you now to get it fixed because the last three years are just not acceptable.”

Despite repeated references to a depleted roster in 2015, a charge from Mara that there were not enough “championship-caliber players,” and the acknowledgment that the team is withering from a lack of successful draft picks who should be entering their NFL prime at this stage, Mara expressed confidence in Reese. Even if it is fleeting.

StoryGlauber: Coughlin makes a classy exitStoryCoughlin emotional over Eli in Giant farewellStoryTom Coughlin press conference recap

“I still believe that Jerry Reese is the right guy to lead us going forward,” Mara said at his Tuesday news conference before posing the question to himself that everyone else would have anyway. “Why do I believe that?

“Jerry put together two Super Bowl-winning teams,” he said. “I would venture to say if we were to poll all of you in this room two years ago about who the top general managers in the league are, every one of you in here would have him on your list. So now, two years later, after another bad season, do we want to throw all that out? I still think he’s capable of putting a great team together and he’s going to get that opportunity.”

He’s the only one left. The professional casualties of the last few years have included the offensive coordinator, defensive coordinator, and now the head coach. There’s only one more head that can roll, and that’s Reese’s if he does not get the job done.

advertisement | advertise on newsday

“I just know that if you lose eight games by 26 points, most of them in the last seconds of the game, you’re not that far away, no matter what you say the personnel is,” Reese said. “Things can be fixed and they can be fixed quickly.”

Reese gave a halfhearted acceptance of responsibility that paled in comparison to Coughlin’s buck-stops-here speech a half-hour or so earlier on the same stage and at the same lectern.

“I take full responsibility for every player that’s been on this roster from the time I was director of player personnel to right now, so I’ll take full responsibility,” Reese said before adding: “The players that we take, I don’t try to have full control of everything. Our coaching staff are involved, our personnel staff are involved, everybody’s involved.”

Giants videos

Reese even seemed to put some of the blame for this 6-10 season on Coughlin.

“The roster that we put out there, it wasn’t a perfect roster,” Reese said. “Nobody has a perfect roster. But you have to manufacture wins in different ways. You got to play the hand you’re dealt and you’ve got to win with it.”

Mara and Reese both said they will analyze the personnel department and left open the possibility that changes there — in staff or philosophy — could be forthcoming. They’ll have a second straight top 10 draft pick in the spring and more cap space in free agency than they have ever had access to in the past.

“It’s not easy to turn a roster over and start to rebuild,” Reese said. “You want to make it competitive.”

Reese also made his case for why he is the man to do just that.

advertisement | advertise on newsday

“I know how passionate I am about it,” he said. “I know we’ve put together championship teams before. I know the big picture of what the National Football League is . . . I’m never afraid of a challenge. That’s part of it. If you have thin skin, you’re afraid, you can’t work in this business.”

The Giants have not fired a general manager since Andy Robustelli in 1978. Mara said that is part of the team’s philosophy.

“If you still believe that the person has what it takes to build a winning team, you have to stay with him, you have to ride through the highs and lows and give him a chance,” Mara said. “And he’s going to have that opportunity.”

Even if it may not be a long one.