Darren Waller’s Giants’ debut could be put on hold.

The Giants’ summer-long run of injury fortune took a turn for the worse Friday when Waller was added to the injury report as questionable for the Week 1 game Sunday night against the Cowboys.

The tight end was designated as limited in practice after he felt some tightness in his hamstring between the Wednesday and Friday practices.

It was a major win that the Giants seemingly made it into Week 1 with a healthy Waller, who missed 17 games over the last two seasons with the Raiders.

His practice workload was closely managed with sports science data.

What’s most concerning is that Waller was sidelined by injuries to both hamstrings last season and what started out as a training-camp injury to his right leg turned into a left-leg issue that nagged the star tight end into November.

If Waller cannot go or the Giants choose to be cautious for the long-term, Daniel Bellinger was solid as a blocker and pass-catcher in 11 starts as a rookie.

And Lawrence Cager, who was limited with an ankle injury earlier in the week, came off the injury report.

But Bellinger and Cager are no substitute for Waller, who is expected to be the focal point of a more explosive passing attack.

Waller did what was asked of him during practice Friday and did not leave the field early.

“We have more practice days than usual practice weeks so it’s like definitely take advantage of the opportunities, make sure we are consistent, make plays in practice,” Waller said earlier this week, “but it’s hard not to be excited for the season to get rolling. We’ve been practicing so much against each other, you start getting a little antsy.”

The Giants are more likely to be without another weapon, receiver Wan’Dale Robinson, who is listed as doubtful. He is coming off right ACL surgery and missed all of camp before he was activated last week.

Cornerback Cor’Dale Flott (hamstring) and safety Gervarrious Owens (hamstring) also are doubtful. In addition to Waller, linebacker Cam Brown and defensive tackle D.J. Davidson (knee) are questionable.

Kicker Graham Gano signed a three-year extension after practice Friday. It is worth $16.5 million, including $11.3 million guaranteed, according to reports.

It is the second extension that Gano has signed since he joined the Giants in 2019. He was scheduled to become a free agent after making $4.66 million this season, so the new deal should be structured to free up salary-cap space.

Gano has converted 91.8 percent of his field goals over his last four seasons. He has 20 field goals of 50 yards or more (on 25 attempts), which is 11 more than any other kicker in franchise history.

The Giants hope that asking their fans to arrive at MetLife Stadium on Sunday wearing blue helps everyone avoid a case of blues.

The first 25,000 fans in attendance will receive a blue T-shirt with this season’s “Be Giant” marketing slogan.

The rest of the crowd is asked to wear blue and create a “Blue-out” intimidating look of uniformity against the night sky.

“Playing well plays into that. That’s what you need to do,” Daboll said. “We have great appreciation for our fans and hope that they are early and loud during the game, but you need to give them a reason to be loud.”

The Giants double and tripled down on Daboll’s message by sending a letter to season ticketholders urging fans to get in their seats early and then asking again in a letter

The Giants asked for a White-out last year against the Cowboys on “Monday Night Football.”

The fans complied.

“Opening day [is] one of my favorite games,” Daboll said.

Cowboys LG Tyler Smith (hamstring) and S Donovan Wilson (calf) are doubtful. LT Tyron Smith (ankle) and DE Sam Williams (foot) are questionable.

Special-teamer Taiwan Jones is the most likely practice-squad elevation for the Giants.