Inevitable means it will happen. It is predetermined, inexorable. The only question is when.

The answer: Now.

The Eli Manning era is over. The Giants on Tuesday benched their franchise quarterback and will start rookie Daniel Jones on Sunday in Tampa. So, the clock starts on Jones as it expires on Manning.

Coach Pat Shurmur laid the groundwork for this historic change a day earlier, when on Monday he said he was going to evaluate all aspects of the team after its 0-2 start, including Manning and the starting quarterback position. It was a clear sign he was contemplating the move and a possible sign his mind already had been made up.

“Eli and I spoke this morning,” Shurmur said. “I told him that we are making a change and going with Daniel as the starter. I also talked to Daniel. Eli was obviously disappointed, as you would expect, but he said he would be what he has always been, a good teammate, and continue to prepare to help this team win games. Daniel understands the challenge at hand, and he will be ready to play on Sunday.”

Jones, selected with the No. 6 pick in the 2019 NFL Draft, was always going to be the heir apparent, anointed as Manning’s successor, but the sense around Giants decision-makers was the changing of the guard would come only after the team was out of playoff contention. Jones’ impressive showing in training camp and the preseason games planted a seed in Shurmur’s mind that the youngster was ahead of schedule. Shurmur praised Jones publicly and raved about him privately. He insisted when Jones got the call, he would be ready.

And then, after the Giants lost their first two games — for the sixth time in the past seven years — the 0-2 record did not sit well with anyone in the organization. Co-owner John Mara was particularly galled hearing boos at MetLife Stadium during the home opener and horrified to again see a near-empty building in the waning minutes of another lopsided loss. Mara adores Manning, but did not have to be convinced by Shurmur that a change, a spark, was necessary.

The first test for Jones will come against the Buccaneers, on the road. With 14 games remaining, there will be plenty of tests and growing pains as Jones learns on the job.

Clearly, the Giants now believe Jones, 22, gives the team a better chance — or at least as good a chance — to win as did Manning.

Manning seemed to sense this was coming, based on Shurmur’s comments the day after the 28-14 loss to the Bills. Manning was not effective in the game and his offense managed to score only 17 and 14 points in two losses this season.

“Ultimately, this is a move that I felt was best for this team at this time,” Shurmur said. “I have said it since I got here, I am very fond of Eli. His work ethic, his preparation, his football intelligence. All those attributes are as good as I have ever seen in a player. And Eli worked as hard as you could ask of anybody to get ready for this season. This move is more about Daniel moving forward than about Eli.”

Manning, 38, has been on the decline for several years, but the team around him has been on a more dramatic decline. He was saddled with a terrible offensive line for years before finally getting some needed protection this season. It was not enough to save his job.

“Hey, we’re 0-2 and you’re looking for answers,’’ Manning said Monday. “I get it. When you draft a guy early and you’re not winning games, these are going to come up. I just got to keep working and do whatever my job is.’’

His job is now to serve as a backup, something he did for the first nine games as a rookie in 2004 behind Kurt Warner and for one game in 2017 when he was benched by Ben McAdoo in favor of Geno Smith, ending Manning’s streak of 210 consecutive starts.

Manning, in the first two games, completed 62.9 percent of his passes and has two touchdown passes and two interceptions. His quarterback rating is 78.7. Jones, in a mop-up role in the season-opening loss to the Cowboys, completed 3 of 4 passes for 17 yards.

That was his NFL debut. What comes next is the true start of his NFL journey.