The Giants’ tight ends have lined up in the slot and tightly against the offensive line this summer. They have motioned into a standing position behind the guard and they have pushed out wide like a traditional wide receiver.

But they have also migrated into the backfield where a fullback traditionally plays. They have been learning how to block like a fullback and hit like one, too. It’s an adjustment that forces the tight end to line up their intended target from 5 yards away instead of having a defender draped over them as soon as the ball is snapped.

Both veteran free agents signed by the team this offseason — Kellen Davis (Seahawks) and Daniel Fells (New England) — have done it before. Larry Donnell, who experimented at the position during camp in 2013, and Adrien Robinson have been asked to learn the new wrinkle as well.

“It’s definitely different,” Fells said. “If you’ve never done it before, it’s kind of a little bit of an uncomfortable position. You’re coming from the backfield and you’re used to being in-line or flexed out. So just coming from a different angle and coming downhill, now you’re going against a linebacker that is 5 or 6 yards away from you.

"He's got a head start, too. So you have to have a different mentality."

The flex positioning allows the Giants plenty of different options on offense, but it also might save them a roster spot, too.

According to multiple people within the organization who requested anonymity in order to speak freely on the matter, the Giants have informed their tight ends that there is a good possibility that a fullback won’t make the final 53-man roster — leaving all of those duties up to the tight ends. Though injuries, personnel shifts and observances in the preseason could change the team’s plans, they entered the year hoping to keep their best four tight ends and give themselves some options on cut-down day.

The idea, which was relayed to players earlier this year during the Giants’ organized team activity, makes sense given that John Conner and Henry Hynoski left for the summer break with only a hazy idea of how they might fit into the offense. Though both have seen snaps during the first week of training camp — Conner even took a handoff Friday — there is a growing uncertainty around new offensive coordinator Ben McAdoo’s preference with the position.

“We mix,” McAdoo said last month just before the break. “We’re in and out of personnel groups and those types of things at this point. You like to use the fullback. The way I was raised, a fullback’s a big part of the things you do. Henry and John have both done a nice job so far.”

Imagining a Tom Coughlin team without a hard-nosed presence at fullback is difficult to do, though it’s more a reflection of the offensive evolution around the NFL. Some scouts around the league believe that the league will eventually retreat back into a run-heavy offenses that emphasize ball control, but for now, bolstering options in the passing game make the most sense.

Neither Conner nor Hynoski has the same hands and height as any of the team’s tight end options. Spending a crucial roster spot on a player that doesn’t have the ability to split out during an audible and be a credible receiving threat makes little sense.

Using the tight end as a fullback would also help explain why the Giants won’t be in any hurry to establish a pecking order at the position. The team’s first unofficial depth chart listed Larry Donnell as the starter in front of Fells, Xavier Grimble, Davis and Robinson in that order, but Fells and Davis have been the first two tight ends on the field each of the last two practices.

“We don’t have to rush into anything,” Coughlin said this week. “With five preseason games and then hopefully throughout the course of the five preseason games we will have all the information we need.”

That information will hinge on how the experiment fleshes out in the preseason. Davis and Fells said the most difficult adjustment to being a fullback is the height difference. Davis is every bit of 6-6, and no other tight end is shorter than 6-4. They are forced to bend lower at the point of contact while maintaining enough balance to handle a bevy of finesse moves from oncoming linebackers and ends.

“It’s mostly footwork and aiming points,” Davis said.

To help, offensive line coach Pat Flaherty said he’s been in constant discussions with tight ends coach Kevin M. Gilbride. The two talk about, and constantly drill the same fundamentals that his guards and tackles go through. Though this is routine procedure for tight ends, it could take on a new meaning if the Giants decide to cut bait with the fullback altogether.

From Jim Finn to Madison Hedgecock to Hynoski and Conner, Coughlin has never done without one.