zack-wheelerBaseball 101: Regardless of the level of play, if a pitcher walks too many batters he will be beaten.

It is a baseball fundamental understood by everybody, with the exception of those insisting the Mets bring up Zack Wheeler, who walked six hitters in his last start.

The clamoring is getting louder in the wake of the Mets’ continued problems with the back end of their rotation. Maybe Dillon Gee, he of the 0-3 record and 8.36 ERA, will get it going Sunday against Washington. But, also struggling are Jeremy Hefner and Aaron Laffey, both of whom were hit hard Saturday by the Nationals.David Wright was correct in saying if the Mets score five runs off Gio Gonzalez they should win, but the combined efforts of Hefner and Laffey made that impossible. Hefner has given up seven homers in 14 innings, with two of them coming Saturday. Laffey gave up three runs in 2/3 of an inning out of the bullpen.

The Mets are hoping for Shaun Marcum’s return, or could give Triple-A starter Collin McHugh a spot start because it won’t, and shouldn’t, go to Wheeler.

The six walks Wheeler gave up trump any radio host’s rant of, “I want to see what he can do.’’ Well, we know what he can do, and that’s walk hitters and get shelled. Hey, the Mets are getting that now.

Do they really need to see one of their prized prospects get routed up here? The Mets took their time with Matt Harvey and should do the same with Wheeler.

And, let’s hear no more about the Mets being cheap because they want to keep him away from the free-agent market another year. That is not the issue. Wheeler is simply not ready for the major leagues, a fact Collins reiterated Saturday.

“That’s a red flag and I don’t want to see walks from those guys,’’ Collins said. “I told Zack in spring training, you’re going to pitch in a tough place [the Pacific Coast League] and I was in that league for 12 years, I know how hard that league is to pitch in.’’

Collins said he would talk to Las Vegas manager Wally Backman about Wheeler. There are times statistics aren’t defining in evaluating performances in the minor leagues. Walks, however, are telling on any level. Overall, in four starts, Wheeler has walked 12 in 18.1 innings. On top of that, he’s given up 20 hits.

“Ten hits, I can understand,’’ Collins said. “But six walks, he’s better than that.’’

He needs to show it.