The Reds have lost 11 of their last 16 and have not scored more than five runs in any of their last seven games.
Manager David Bell ran out his platoon lineup against left handers, a batting order that from five through nine featured batting averages of .177, .191, .143 and .167.
The game’s only runs came in the first inning when ever-dangerous Nolan Arenado ripped a two-run home run off Sonny Gray.
Arenado blasted a two-run home run in the eighth inning Saturday that broke a tie and gave the Cardinals a 6-4 victory.
He struck much earlier Sunday. His two-run home run came in the first inning after a two-out single by Tyler O’Neill.
The Cardinals managed only one other hit the rest of the way, but the Reds couldn’t solve Happ and the St. Louis bullpen.
With the win, the Cardinals are one game behind the Reds in the race for the National League’s second wild card spot.
“We’re OK, we’re not down on ourselves at all,” said rookie second baseman Jonathan India, who had one of Cincinnati’s five hits. “This is just part of baseball. It’s tough, for sure, but we are going to come through, I know we are. going to take that playoff spot.
“At the end of this, we’re going to laugh at this, laugh at these losses,” he added.
It was no laughing matter Sunday. The Reds had a few chances but couldn’t take advantage of any.
And it is no laughing matter that the Reds suddenly can’t score runs in abundance.
“Am I surprised? Yes,” said India. “We are a dangerous offense. It is getting late in the year and we are all battling. At the end of the day, we’ll be fine. I know we will.”
Asdrubel Cabrera opened the third by reaching on third baseman Arenado’s throwing error and India singled with two outs. Both were stranded when Tyler Stephenson grounded into a fielder’s choice.
Nick Castellanos walked to begin the fourth but the next three Reds went down.
Stephenson singled with one out in the sixth but Castellanos and Joey Votto couldn’t produce.
Pinch-hitter Max Schrock singled with one out in the seventh and and Cabrera hit into an inning-ending double play.
The frustration mounted in the eighth when Delino DeShields doubled. Once again the next three Reds were retired.
Finally, with two outs in the ninth, pinch-hitter Mike Moustakas doubled against closer Giovanny Gallegos. That brought up Schrock, representing the potential tying run. He struck out on three pitches.
Bell continues to slap a happy face on all things negative as his team misses chance after chance to put distance between it and the struggling San Diego Padres and the onrushing Cardinals.
“Listen, I trust our team,” he said. “I trust where we are. Clearly, we’re not satisfied, by any means, with the last six series. But there is no time to think about that.
“The bottom line is that I trust these guys, offensively and defensively and our pitching,” he added. “I feel great about moving forward with this entire group. It is pretty easy to be positive when you are around this group every day. That’s the way I see it.”
Moving forward means moving to Pittsburgh where the Reds hope to recharge their batteries against the last-place Pirates. The three-game series begins Tuesday night in PNC Park.
Reds at Pirates, 6:35 p.m., Bally Sports Ohio, 700, 1410