CINCINNATI - Early next week, for the first time since promoting him from Double-A Binghamton, the Mets will face a question that might linger into next season: What comes next for Dilson Herrera?

Second baseman Daniel Murphy continues to make progress with his strained right calf. If the All-Star comes off the disabled list Tuesday, Herrera will find himself on the bench. But on merit alone, the prospect has given the Mets little reason to move him out of the lineup.

"He's pretty impressive to be around," manager Terry Collins said after the Mets' 2-1 loss to the Reds Saturday. "He's got great makeup and certainly he's not intimidated by being here."

Herrera finished 1-for-3, including a second-inning single that drove in Travis d'Arnaud. But it was the Mets' only run, which wasn't nearly enough as the Reds' Johnny Cueto outdueled Dillon Gee.

Facing the same lineup that exploded for a season-high 14 runs and smashed five home runs a night earlier, Cueto (17-8) retired 13 straight at one point and held the Mets to one run in seven innings.

Gee blanked the Reds through five innings but allowed a solo shot by Todd Frazier in the sixth. In the seventh, he made a critical mistake to pinch hitter Chris Heisey, who drilled what proved to be the game-winner over the fence in leftfield.

"It was a total lack of execution there," said Gee, whose mistake overshadowed perhaps his best overall start in a difficult second half.

Still, the Mets gave themselves a chance to tie it against Aroldis Chapman, who suddenly became unhinged after Curtis Granderson's one-out single in the ninth.

Pinch runner Eric Young Jr. swiped second base before Herrera worked a walk. Collins called for a double steal, and at first it appeared Young made it safely to third. But a video review showed that Young's slide took him off the bag just long enough for third baseman Kristopher Negron to apply the tag and squash the rally.

After Wilmer Flores drew a walk off Chapman, Collins again was tempted to call for the double steal. He decided against it, though, because the inexperienced Herrera would have been the lead runner.

Then Eric Campbell struck out to end the game, stranding Herrera at second base.

Though he's the youngest player in the majors at 20, Herrera is hitting .267 and has an RBI in five of his eight games.

"We're all very, very impressed with the offensive side so far," Collins said.

Though the Mets need a long-term answer at shortstop, Collins dismissed the notion of experimenting with Herrera, who is regarded as a work in progress at the less demanding position of second base.

Besides, Collins seemed cool to the idea of cutting into playing time for Flores. The Mets have committed to giving him an extended audition despite his own defensive shortcomings.

"The whole thing was to give [Flores] this opportunity," Collins said. "Again, you're muddying the waters by throwing somebody else out there. I'm not here to run a tryout camp. I'm trying to win some games."

Murphy remains under contract through next season, thus blocking Herrera at second base.

Nevertheless, Collins said Herrera could skip Triple-A Las Vegas, especially if he plays winter ball and spends time in spring training working on his defense with third-base coach Tim Teufel.

Said Collins: "I don't think there's any reason why he couldn't make the jump."