It won't be anyone in the rotation just yet.
"He's not replacing anybody," Collins said. "What we're going to do, most likely, when Zack comes, [is go] with an extra starting pitcher for a turn so that everybody can stay in line."
Eventually, though, one starter will be sent to the bullpen.
As far as who will be sent to Las Vegas to clear a roster spot, Collins said that's a decision for general manager Sandy Alderson to make.
Wheeler has made 12 starts for Las Vegas, and has a 4-1 record, 4.14 ERA and 66 strikeouts in 63 innings.
And from the reports Collins has been getting, he's going to be even better with the Mets.
Scouts have said that Wheeler will likely improve at the Major League level. Collins said there are a couple of reasons that might factor into that, including Wheeler's focus starting to wane as he continues to overpower Minor League-level talent.
"There are guys that get bored, who know they belong at the next level," Collins said.
Collins added that pitchers can have more confidence in the Majors, knowing there are typically better fielders playing behind him. And in Wheeler's case, he won't be pitching in Las Vegas, where the dried-out field plays quick and grounders often scoot through the infield for hits.
Collins wants Wheeler to understand that he doesn't have to throw a no-hitter every time out, just pound the strike zone with quality pitches, and he'll get outs.
As Wheeler's promotion draws near, the anticipation continues to grow. Collins isn't exempt.
Said Collins: "I'm anxious to see him."