CINCINNATI — In a rotation littered by question marks, Nolan McLean should be the closest thing the Mets have to a slam dunk every fifth or sixth day.

And yet, that version of McLean has largely been lacking, due to shortened outings caused by high pitch counts.

Wednesday was more like it for the rookie right-hander, who threw strikes, allowing him to match his longest start of the season in the Mets’ 9-1 victory over the Reds at Great American Ball Park.

The Mets avoided a three-game sweep on a day they totaled 15 hits and jumped to a comfortable lead by the middle innings.

McLean’s performance followed letdowns by Tobias Myers and Kodai Senga that were largely responsible for the Mets losing the first two games in the series.

McLean lasted seven innings (the third time this season he’s extended that deep) and allowed one unearned run on three hits and one walk with nine strikeouts. He matched a season high with 101 pitches.

Offensively, the Mets received a 3-for-4 performance from Bo Bichette, who reached base four times to continue a torrid stretch. Juan Soto and Francisco Alvarez also provided three hits apiece.

The Mets sent eight batters to the plate against lefty Nick Lodolo in the third inning when they scored three runs on four hits and a walk. Soto, Marcus Semien and Mark Vientos delivered RBI singles in succession to give the Mets a 3-0 lead. Luis Torrens’ infield single and a walk to Bichette ignited the rally.

Vientos’ error in the bottom of the inning – he mishandled Zack Short’s throw to first base – led to the Reds scoring an unearned run on JJ Bleday’s sacrifice fly. McLean allowed a double to Matt McLain – on a ball Soto tried to shoestring in left field – before plunking Edwin Arroyo.

Bichette’s single in the fifth started another rally. Soto and Semien followed with singles to load the bases before Vientos’ sacrifice fly extended the lead to 4-1. Alvarez stroked an RBI single and A.J. Ewing’s two-run double put the Mets ahead 7-1.

Bichette delivered an RBI single in the eighth to complete his big afternoon, and Soto’s ensuing double extended the Mets’ lead to 9-1.