Jason Bay started in left field for the Mets last night after missing all but one at-bat’s worth of the last two games with a shin injury. He went 0-for-4 with a walk and two strikeouts and left an orchestra on base. Since returning from the disabled list on July 17, Bay is hitting .093 with a .204 on-base percentage and one extra-base hit — a home run against the Nats in his second game back. Though it’s still only a 121 at-bat sample, he now has a .531 OPS for the year, the lowest it has been after more than five games in any season of his career.

Bay is a really nice guy. By nearly all accounts, he’s dedicated to improving himself and working as hard as he did in the strong seasons that earned him the four-year, $66 million contract with a vesting option for 2014 he inked with the Mets before 2010. He is purportedly a very good teammate and, when he’s not struggling, he is hailed as a leader in the clubhouse. And the Mets are still on the hook for all $16 million of Bay’s 2013 salary and the $3 million buyout on the option.

But something has to give. This doesn’t seem revelatory to anyone who has watched Bay struggle these past few weeks and these past few years, yet someone or some collection of people in the Mets’ organization is keeping Bay on the roster and starting the bulk of the team’s games.

Why? The Mets are 15-18 in games Bay has started and 36-36 in the others, so they haven’t exactly been way worse with him in the lineup than without him. Maybe that’s a factor, though it doesn’t seem a particularly good one. He hits right-handed on a roster full of lefties. Sure, he has fared worse against lefties this year than every position player who has spent any significant time with the club besides the backup catchers and Kirk Nieuwenhuis (with whom he is about even)But Bay’s handedness must be a consideration. Plus he runs the bases well in the increasingly rare instance he reaches one safely, and he plays sure-handed if not rangy defense in left field. And there’s all that money.

None of those, in isolation or in conjunction with the rest, seems like a good enough reason to keep Bay in the lineup every night or even on the roster. Presumably Sandy Alderson would like to see Bay bounce back to the point where he could find some team somewhere willing to take on even a little of Bay’s salary in a Gary Matthews-type deal, but what could Bay really do in the next two months to convince anyone he’s worth appreciably more than a guy available at the league minimum? Nothing that seems likely after three straight seasons of underwhelming to awful performance, that’s for sure.

The Mets don’t have many appreciably better options, but a case could be made that both the recently dispatched Nieuwenhuis and Lucas Duda offer more advantage to the Mets even against lefties. Duda is not a good defensive outfielder, but he out-hit Bay against lefties this year and seems apt to potentially be such a massive offensive upgrade against righties to mitigate his flaws. Nieuwenhuis struggled against lefties this year and in the Minors last year, but he is likely a better defender than Bay.

But even if you allow that Duda and Nieuwenhuis are in Triple-A to work on fixing the issues preventing them from excelling at the big-league level and that the team is prioritizing their development over its needs at the big-league level, and even if you figure that the team wants to be able to bring Bay to Spring Training next year to see if he’s somehow rejuvenated and ready to contribute somehow before they cut him loose for good, there’s really no justification for starting him against right-handed pitchers like they did last night. With switch-hitting Andres Torres and lefty-hitting Jordany Valdespin and Mike Baxter on the roster, the Mets could field an all-lefty-hitting outfield with strong defense. And Scott Hairston, too, represents a better option against righties than Bay at this point.

If the Mets want to keep Bay around for whatever reason, they should give him the best chance to succeed by playing him only against left-handers. If they’re still interested in winning as many games as they can — and they showed that they are when they held on to Hairston at the trade deadline — there’s just no good excuse to give Bay so much playing time.