It’s harder than it used to be to hire a coach in the NFL.

That may be one reason why Jim Fassel and Dan Reeves were fired before the season ends, giving the Giants and Falcons a head start in searching for their successors.

But it’s not the only reason.

As New York running back Tiki Barber pointed out after Fassel was dismissed Wednesday, getting through an unpleasant firing early can make things easier for the team and its new coach the next season.

“You see in other teams when the coach is going and everyone knows he’s going, bad feelings permeate a locker room,” Barber said. “Those things linger when the coach stays around — even for next year and the next coach coming in.”

But the early firings in New York and Atlanta also give those teams a jump on using new NFL guidelines that require a more intensive search than in the past.

So beginning now, they can winnow down candidates and interview assistants on teams with first-week byes in the playoffs. Those interviews can be conducted Dec. 29 to Jan. 2, then not again until their teams are eliminated.

The Giants reportedly have a few in mind, including Romeo Crennel and Charlie Weis of New England; Brad Childress of Philadelphia and Lovie Smith of St. Louis. If they don’t get them that first week, they might have to wait until after the Super Bowl.

Fassel will coach the Giants in their final two games. Reeves decided to step down immediately when he was told he’d be fired after the season.

“I think it’s individual preference, especially when you’re dealing with two veterans who have been successful,” said Bill Polian, president of the Indianapolis Colts. “In each case, I think the teams involved made a decision and didn’t want to string these guys out.”

Don’t discount the hiring headstart. The Giants had a bad experience more than a decade ago.

After the team won a Super Bowl in 1991, Bill Parcells quit — but not until May, after the hiring season. His obvious successor, defensive coordinator Bill Belichick, already had been hired by Cleveland. So the Giants had to settle for Ray Handley, who turned out to be one of the worst fits for a head coaching job in NFL history.

Another possible candidate for Fassel’s job is former Jacksonville coach Tom Coughlin. Another could be former Vikings coach Dennis Green.

The Giants now can openly recruit them. So can Atlanta.

The Falcons’ first choice is believed to be LSU coach Nick Saban, whose team will play in the Sugar Bowl on Jan. 4.

In the past, teams with vacancies weren’t allowed to interview prospective candidates until after their teams were eliminated from the postseason. Fassel’s firing prompted Belichick, now the Patriots’ coach, to give Crennel and Weis enthusiastic endorsements.

“He is a guy who has been in the league a long time and he has done a lot of different things,” he said of Crennel. “He’s done a great job for me.”