CHICAGO — For as many calls as general manager Brodie Van Wagenen took heading into Wednesday’s trade deadline, he ultimately couldn’t part with his big guns.

Noah Syndergaard and Zack Wheeler, welcome back to the Mets — not that they ever left. Edwin Diaz, your place in the Mets bullpen is secure.

Rebuilding is for disasters, and it’s clear Van Wagenen doesn’t view the Mets in such a category.

“We wanted to make sure we only considered moves that were going to improve our club and keep us on mission,” Van Wagenen said. “And anything short of that ultimately was not going to be something we were willing to entertain.”

In total, the Mets subbed Marcus Stroman — acquired from the Blue Jays last weekend for two minor league pitching prospects — for Jason Vargas, who was dealt to the Phillies for Double-A catcher Austin Bossart.

Wheeler remained the strongest possibility to depart in the waning hours of the deadline (the Rays and Astros were most heavily interested), but Van Wagenen couldn’t find a deal he felt made sense for the right-hander. So Van Wagenen called Wheeler around 4 p.m. to tell him he was staying.

“It was all there for it to happen and it just didn’t happen,” Wheeler said. “I was ready for it, especially with me being a free agent after the year, it might happen, but it didn’t.”

By keeping Wheeler, the Mets risk losing him in the offseason for nothing, but there are other avenues the club can pursue. If Wheeler isn’t signed to an extension during the season, the Mets can still extend him a qualifying offer. If Wheeler accepts (last year’s number was $17.9 million) the Mets would retain him for 2020. If he declines, the team would be in position to receive draft-pick compensation.

But Van Wagenen said the qualifying offer isn’t the Mets’ focus at this point.

“We think he is a good pitcher, we have interest in him being a Met for the long term,” Van Wagenen said. “How that sorts itself out over the course of his next couple of months and free agency, time will tell, but I don’t think our factoring or decision making was built on simply a qualifying offer versus a prospect return, but more looking at, ‘OK, how do we shape up as we head toward the offseason and what’s our outlook as we look into 2020?’ ”

The Mets began the day five games removed from the NL’s second wild-card berth and will try for an unlikely run to the postseason over these final two months. In Stroman, they have a pitcher they believe will help the dual cause of trying to win this year while setting up the club for 2020.

“By adding Marcus to the equation early it gave us an ability to survey our team over the last couple of days and survey the marketplace to make sure we put ourselves in a better position as we looked to the offseason,” Van Wagenen said. “It allowed us to kickstart that process while still capitalizing on what could be an exciting summer.

“We are the underdogs. We are now chasing the rest of the pack. We do still see ourselves as the underdogs and we found a player in Marcus Stroman that can help us maintain that edge and see how aggressively we can make a run at this thing in 2019 and certainly he puts us in a position to win games in 2020.”

Stroman is under club control through 2020, and the Mets have Syndergaard — who has rebounded over the last month after a sluggish start to the season — as theirs through 2021.

Van Wagenen had no good answer as to why he dealt Vargas within the division to the Phillies, a team competing for the same wild-card spots. But the GM declined to term the move as a salary dump, though the Mets’ only returns on the deal were about $2 million in savings and a Double-A catcher batting .195.

“We need to create an open spot in the rotation for Marcus,” Van Wagenen said. “There’s not that many ways to do that unless we move one of the starters.”