zack wheelerEven without the oblique injury, Zack Wheeler would be opening the season in the minor leagues, which was always the proper decision.

Maybe he wouldn’t have been sent down today with nine others, but as spring training goes on and the need to stretch out the starters increases, Wheeler’s innings would have been reduced, something the Mets did not want to happen.

Since he is better off getting regular innings, today’s demotion was inevitable. With the oblique hampering him, there’s no sense in trying to squeeze him in. He’s better off resuming a normal routine in the minor league camp, where he’ll throw in the bullpen again before getting into a game.There’s always the possibility of Wheeler pitching in a “B” game, but for now he’s in the right place for his development. The Mets have long been accused of rushing pitchers – see Mike Pelfrey and Jenrry Mejia – and as they are building again they can’t afford to make a similar mistake with Wheeler, regardless how he feels.

“It’s the big leagues, of course I want to be here,’’ Wheeler said. “I’m not surprised. They told me this could happen.’’

When Johan Santana went down, there was immediate speculation Wheeler might be the one to replace him on the roster, but general manager Sandy Alderson immediately shot that down, saying the plan of patience used for Matt Harvey would be the same for Wheeler.

“I felt bad for him because of the injury,’’ manager Terry Collins said. “I told him he’s sitting in the same seat Matt Harvey was last year. I told him to do well and force us to call him up.’’

The Mets played Harvey perfectly. They resisted the initial temptation, and eventually brought him up in July when the season was already lost. Harvey impressed in ten starts enough to be in the rotation. They project the same for Wheeler.

Wheeler already had a setback when he strained his right oblique muscle 11 days ago and had to be scratched from a start against St. Louis. Wheeler conceded the injury was a setback. Wheeler made one start this spring, throwing two scoreless innings against Washington.

“I only got out there one time,’’ Wheeler said. “ That’s what I’m kind of mad about. I wanted to sort of get out there and prove myself. I hope I’ll be up here soon.’’

Several things have to happen if Wheeler is to see Citi Field soon, including injuries to a pitcher in the major league rotation; Wheeler’s performance at Triple-A Vegas, and, of course, economic considerations.

“I told him to work on his secondary pitches and fastball command on both sides of the plate,’’ pitching coach Dan Warthen said.

Wheeler is aware what needs to improve if he’s to succeed in the major league. He’s aware he can beat hitters with his stuff in the minor leagues, but realizes he needs more finesse and guile in the major leagues.

“I need to keep working on my curveball and getting it over for strikes,’’ Wheeler said. “I want to keep my pitch count down and get deeper into games.’’

Economically, if Wheeler stays in the minors for the first 20 games of the season he can’t be credited with a full year of major league service time, which would delay his free agency season from after 2018 to 2019.

It is anticipated the cutoff date for the extra year of salary arbitration might be June 15, so it is entirely feasible Wheeler will be called up after that date. That’s also the same time we might see catching prospect Travis d’Arnaud.

Unless there’s a dire need, don’t expect to see Wheeler before June 15.

MARCUM PITCHES WELL: Shaun Marcum was exceptional today, throwing 3.2 scoreless innings while giving up one hit and striking out two in the Mets’ 3-0 victory over St. Louis.

“I saw a lot that I liked,’’ Collins said. “He had tremendous command and that’s his trademark. He made pitch after pitch.’’

Marcum, penciled in as the fifth starter, is confident in his progress.

“I feeling like I’m heading in the right direction,’’ Marcum said. “I need to build up my pitch count.’’

Mechanically, Marcum said he doesn’t have command of his change-up and is pushing it rather than throwing it with a natural release.

When his change-up doesn’t have the right movement and goes horizontally rather than dip, it is a sign he is flying open with his shoulder and not staying on top.

METS NOTEBOOK: Jordany Valdespin continues to impress, today driving in a run with a seventh-inning single. … Alderson said it still is too early to make a determination on placing Santana on the disabled list to open the season. … Frank Francisco threw off the mound. The reports were good, but Collins said: “Be careful what you see in March and be careful what you see in September.’’ Translation: He’s opening the season on the DL. … Wheeler highlighted the list of ten cuts, which included: pitchersGonzalez GermenCollin McHughElvin Ramirez and Hansel Robles; left-hander Darin Gorski; infielders Reese Havens and Wilfredo Tovar; outfielders Juan Lagares and Cesar Puello. The Mets are down to 45 players in camp.