MLB

Mets must do right thing: Can K-Rod

There are good fights to pick, and there are bad fights that are best avoided. The Mets have a fight worth contesting now, they have an opportunity to send a loud message to their fans that they are done being — pardon the puns — a punching bag and a punch line.

A higher authority has done for the Mets what they didn’t have the stomach to do themselves, making Francisco Rodriguez disappear for longer than two games, sending him to the shelf for the rest of the season with torn ligaments in his pitching thumb, an injury that is almost certainly related to his alleged attack on his girlfriend’s father last week.

So K-Rod is kaput for now, and now the Mets must prove they have the intestinal fortitude for more. If ever there was a situation that screamed for a baseball club to do the right thing, to send an unbending message, it is now.

BOX SCORE

FIGHTING FRANKIE OUT FOR SEASON

First, they have to fight to void that portion of the contract that will coincide with his time away from the team. That means the rest of this year, at a minimum.

And then they have to rid themselves of the headache for good. If that means exiling Rodriguez in the offseason — a move that would almost certainly entail them having to eat most of his remaining deal — that’s fine. If that means going after the balance of the contract in what would be a precedent-setting move the commissioner’s office would probably rather them not fight — even better

Any attempt to void any part of the contract will almost surely involve a fight with the union, even if the union needs to pinch its nose with one hand to ward off the stench. That is what the Players Association does. These are the battles they relish, where mud slings everywhere and dirties everyone involved. They take no hostages. It can be an unpleasant experience.

And that’s the easy part, actually, and it seems like a skirmish the Mets might actually be willing to wage. A source familiar with the Mets’ thinking told The Post’s Joel Sherman yesterday the team was “well down the road” studying its options. Let’s hope so. As weak-kneed as the Mets looked in settling for a two-game ban in the immediate aftermath of K-Rod’s humiliating incident, this would go a long way toward rebuilding the franchise’s crumbled credibility.

Because if they bring K-Rod’s remorse-free scowl back into their clubhouse next year, it is begging for trouble. If they force their fans to choose between rooting for a player they’ve grown to detest or stay away from the ballpark completely . . . well, it isn’t likely the Mets will like the results of that straw poll at all.

The Mets need to remember they hold the moral high ground here. Right until the moment they refuse to do anything about it.

This is the right fight to pick. The Mets don’t always know the difference. Last winter, they needlessly needled their best player, Carlos Beltran, because they didn’t like that he chose surgery over rehab to try and fix his banged-up knee. There was talk of trying to finagle a way out from under that contract, but there were no grounds for it at all, just the Mets finally tiring of paying a player with shot knees. But they sure wanted to, all but winding up their main media message boy and setting him loose on Beltran.

This is different. This time, they have no other choice if they want to keep liking what looks back at them in the mirror. K-Rod did more than damage himself when he took that mindless swing at Carlos Pena; he also put the finishing touches on the latest Mets calamity. He needs to pay with more than the forfeiture of his good name. It won’t be an easy fight. It’s one the Mets need to fight anyway. What’s right is right.

michael.vaccaro@nypost.com