Justin Tuck doesn’t have his heart set on retiring a Giant anymore.

In comments to The Post on Thursday morning, the veteran defensive end guaranteed he would become an unrestricted free agent when the league-wide market opens March 11.

Re-signing with Big Blue before then now appears to be out of the question.

“I will see what the market is for me,” Tuck said during a promotional appearance for MetLife. “I’ve never been in this situation before, and it’s a great opportunity for myself. I would be doing myself a disservice if I didn’t see what the market is, and I will.”

That sounded like a far different cry from the one that came from Tuck at the end of the Giants’ 7-9 season in December, when he said he would “love to retire as a Giant” and was hopeful the two sides “would be able to make something happen” in the offseason.

Tuck, who turns 31 in late March, said he plans to grant the Giants’ recent request for a face-to-face meeting next month to discuss returning, but described it as more of a courtesy because of all the difficult decisions the cap-strapped team faces this offseason.

“We will sit down in a couple of weeks and see what happens, but obviously, the Giants are going to do what’s best for the Giants, and vice versa with me and my family,” Tuck told The Post. “I understand where they’re coming from and what obstacles they have to overcome this offseason. There’s no guarantee, and that’s obvious. It’s a business, and [I] understand both sides of it.”

Tuck is coming off one of his best seasons as a pro with 11 sacks in 16 games — two more sacks than he compiled in the two previous injury-plagued seasons combined — but he could find the market unfriendly to his demographic.

The demand for pass rushers over 30 quickly dried up last offseason, forcing several talented veterans to settle for cheap, short-term deals. Tuck, though, is confident he won’t face the same issue.

“I’m a pretty good football player,” Tuck said, “and I’m pretty sure there will be some interest in a pretty good football player.”