In the midst of another offseason featuring more rebuilding, the New York Giants aren’t expected to be big spenders in free agency this offseason.

There are ways, however, that the team can get more room under the salary cap by releasing veterans and re-structuring a major contract or two.

Currently, the Giants go into free agency with an estimated $24.7 million in cap space, a number that is No. 19 among all war chests heading into the offseason. That number likely doesn’t do them a whole lot of good as they need to address the offensive line and pass rush issues plus re-sign safety Landon Collins, who is now a free agent after completing his rookie deal.

According to salary cap consultant Jason Fitzgerald, the Giants can nearly double their cap space by cutting linebacker Olivier Vernon, running back Jonathan Stewart, linebacker Connor Barwin, and cornerback Janoris Jenkins. Those four would free up roughly $23 million in cap space, a major boost to their ability to rebuild.

And even if they re-sign Collins to a mega-deal, Fitzgerald thinks the Pro Bowl safety could land a contract in the ballpark of $10.8 million a year, the Giants would still have plenty of flexibility to sign their draft picks and add a couple of pieces on both sides of the ball.

Fitzgerald, who also runs the thorough and in-depth OverTheCap.com, also thinks the Giants could save in another way.

Wait for it. Wait. Wait.

They could make a tough choice on Eli Manning.

Were the Giants to cut their two-time Super Bowl MVP, it would be a cap savings of $17 million as Manning is in the final year of his contract. But Fitzgerald also sees another way which would keep Manning for another year or two but help out the salary cap issue.

“The other option would be to extend Manning for cap relief. Such an extension would keep his salary identical this year ($17 million) but most of it coming as a signing bonus and prorating over four or five years,” Fitzgerald told MSGNetworks.com.

“The extension would have no new guarantees beyond that $17 million. Really what you are doing is just deferring cap charges to 2020 when you would likely hope he retires. In the event he is still playing okay 2020’s cap charge would also probably be reasonable.

This is something that the Steelers did with Troy Polamalu and Heath Miller at the end of their career to avoid cutting them and letting the careers end more gracefully. I think there could be some merit to doing this if they don’t plan on starting a rookie

and don’t want to play in free agency.”

The conventional wisdom is that with the sixth pick in April’s NFL Draft, the Giants will go get a quarterback. Manning, who just turned 38-years old this month, likely has a season or two left with the Giants. The Giants under general manager Dave Gettleman don’t seem to want to push Manning out the door but they could begin the process of grooming his heir apparent.

The team ideally could draft his replacement this year and let the quarterback sit and develop a season or maybe two under Manning.

“I feel like their rebuild is so quarterback-dependent that I don’t think their cap is an issue. You can make magic happen with the cap if you want and Gettleman’s tenure in Carolina showed tendencies to push cap charges,” Fitzgerald said. “It is basically a question of can they draft someone or not at quarterback. If they can not then I think they have an issue. They didn’t take one last year and I can’t imagine the plan is another top 10 pick next year. They have enough pieces to be a mid-rung team with Eli

or a veteran but that does nothing to help them long term.”