Brad Penner-USA TODAY Sports

When the Mets acquired Darin Ruf from the Giants for four players they hoped he would help with their difficulties against lefties, but that hasn’t happened to this point. Then the Mets called up lefty mashing prospect Mark Vientos as another option, but still no improvement against lefties. All three of Oakland’s starters in the series vs the Mets are left-handed meaning the time for Ruf and Vientos to finally step up is here.

The Mets enter the day with a .704 OPs vs lefties compared to a stronger .754 OPS vs right-handed pitching. They’ve won 66% of their games facing right-handed starters and only 58% of their games against left-handers.

Ruf comes into the day with more than twice as many strikeouts (17) than hits (8) and a .404 OPS with the Mets. The veteran is 2-for-his-last-36 and doesn’t have an extra-base hit since August 12. To say he’s due for a big series would be an understatement. Despite his struggles with the Mets, the 36-year-old has a .771 OPS vs lefties this season, that’s still significantly higher than the Mets team OPS against southpaws.

Vientos, 22, is only 1-for-18 with eight strikeouts to begin his big league career. He’s 1-for-9 with two walks against lefties and is still searching for his first hit vs righties. The youngster crushed lefties in the minors this year with a .314/.397/.686 slash line and 13 of his 24 home runs.

It’s certainly possible that Mets manager Buck Showalter could start both Ruf and Vientos in the first game of the series with Brandon Nimmo nursing a sore left quad. The Mets have said Nimmo is day-to-day after he left their loss on Wednesday in the first inning with the quad issue. Ruf could play right field with Mark Canha shifting to center in a park he’s very familiar with.

After that first game, it could come down to the health of Nimmo and which one of Ruf and Vientos perform better to see who continues getting the starts vs lefties for the rest of the series. One thing is certain, whoever Buck decides to start between the two, the Mets desperately need them to step up against the three Oakland starters.