Mark Vientos continues to impress with his bat — his future as a third baseman remains unclear.

Back hitting second in the lineup a day after homering twice from the spot, Vientos has proved himself to be more than capable offensively, but when asked about the team’s “long-term” situation at third base, president of baseball operations David Stearns wasn’t ready to anoint Vientos for the permanent spot.

“Mark has done a very nice job solidifying himself as a major league player,” Stearns said Friday in regard to third base beyond this season. “He’s improved defensively to the point we’re running him out there regularly at third base. He deserves a lot of credit for that. For now, I’m focused on this year. In the offseason, we’ll evaluate future years.”

After taking over for Brett Baty at third in mid-May, Vientos has been as productive as anyone in the lineup.

He went 1-for-3 with a run scored in Friday’s 7-3 win over the Marlins.

He leads the team in OPS and OPS-plus and Carlos Mendoza has been impressed enough to move him to the top part of the lineup the past two games after hitting Vientos fifth, sixth and seventh for much of the season.

“What has continued to be great to see from Mark is the adjustments he’s able to make through the season on both sides of the ball,” Stearns said. “He went to Triple-A with an emphasis on defense and now he understands how major league pitchers attack him. Mark is still a very young player. He’s not going to be perfect. We don’t expect him to be perfect.”

To that end, while Vientos has been serviceable at third base, the advanced metrics still aren’t good.

According to Fangraphs, of the 20 players that have played at least 550 innings at third base this season, no one has a worse defensive runs saved rating than Vientos’ minus-6 and Statcast has him 20th out of 24 ranked third basemen in terms of Fielding Runs Value.

One NL scout who has watched Vientos at third this year and last season said, “He’s made some strides there and his offense makes up for some of the deficiencies, but there are definitely concerns. He just doesn’t move well.”

The player he replaced at third, Baty, is working at second base — as well as third — at Triple-A Syracuse.

Stearns said the organization has liked what it has seen from Baty at second and now consider him a multi-position player.

But Baty’s woes at the plate have surfaced in the minors, where he has a .574 OPS and 23 strikeouts in his previous 80 plate appearances.

And his slump goes back farther than that, with a .668 OPS in 36 games since June 29.