ST. LOUIS -- By all measures, Pirates right-hander Paul Skenes has had a stellar rookie season. But he admitted that lately he’s had to dig deeper into his bag of tricks, especially when facing division opponents multiple times.

On Monday, making his third career start against the Cardinals, that included using his changeup to strike out a right-handed batter for the first time.

“I mean, had to do some things that I haven't done necessarily, you know, to this point in the season,” Skenes said. “They've seen everything. So, then it turns into, you know, playing the game of baseball, and we had a good game-plan and executed it pretty well.”

Skenes turned in his third quality start in three opportunities against the Cardinals, but the Pirates still lost 4-0.

Skenes allowed one run on four hits in six innings. He struck out seven, walked one and threw 66 of 102 pitches for strikes.

Still, the Rookie of the Year candidate wasn’t completely satisfied.

“They had a couple hits, you know, early in innings, and then it turns into making pitches to get out of it,” Skenes said. “I wasn't helping myself out either. I wasn't getting ahead when I needed to, some of those at-bats.”

Pirates manager Derek Shelton said Skenes used his fastball and changeup off each other.

“I thought the changeup was actually really good too,” Shelton. “He was able to use it. He used it right-on-right some, but overall, he threw the ball well. It was a one-run game going into the seventh.”

The Cardinals are the only team that Skenes has faced multiple times and not earned a win in any outing. He got a no-decision against St. Louis on June 11 and took his first career loss against them on July 23.

But it’s not for lack of quality performances.

Skenes has a 1.30 ERA in his three starts against the Cardinals. He has 23 strikeouts to just one walk and has allowed 13 hits in 20 2/3 innings.

“He can't control what happens on the other side of the ball,” Shelton said. “And the days that he's pitched, you know, and he's pitched well here, we just haven't gotten any runs.”

Skenes retired the first 10 batters he faced until Alec Burleson reached on a single. Burleson moved to second on a balk and eventually scored on a two-out single by Nolan Arenado.

Skenes was able to work out of a mini-jam in the sixth by striking out Paul Goldschmidt and fielding a comebacker from Arenado.

“Just got to execute,” Skenes said. “That's the bottom line.”

Andre Pallante was the biggest reason why Skenes didn’t collect that elusive win against the Cardinals.

Pallante pitched seven scoreless innings, gave up just four hits and walked one. His nine strikeouts were a career best.

“The breaking ball was really good,” Shelton said. “He kept us off-balance with it and he was able to execute it the entire game.”

The Cardinals threatened to break the game open in the seventh after loading the bases with no outs against Ryan Borucki, but managed to get just one run on a Pedro Pagés single as Colin Holderman was able to limit the damage.

Brendan Donovan’s RBI double in the eighth made it 3-0 and Lars Nootbaar followed with a sacrifice fly to cap the scoring.

Isiah Kiner-Falefa had a pair of hits for his fourth multi-hit game in his past eight.

Any notion of limiting Skenes' workload the rest of the way was put to rest. He now has 126 innings under his belt and he eclipsed the 100-pitch mark for the ninth time.

“We've been very thoughtful about his workload the entire year, even at the beginning of the year,” Shelton said. “And, you know, I think it's something that we've talked about. It's important for him to finish the year and that's our plan.”

Skenes said he’s learned a lot from his first time through the grind of a 162-game season.

“The in-season work is super important, but people don't understand how important the offseason work is,” Skenes said. “So, I think it's kind of, you know, showed me how important that is and then helped me develop my plan. Also, just, you know, body, mind, you know, developing pitches and that kind of thing, just keeping the consistency. I've learned a lot about that.”