ST. LOUIS -- Not that they didn’t know this already, but the second half of the season will be a balancing act for the underdog Marlins. 

While in the thick of the National League Wild Card race, Miami must keep an eye on its young starting pitchers with injury histories surpassing their career highs for innings. That’s why left-hander Jesús Luzardo didn’t make his return to the mound over the weekend in Baltimore following the All-Star break. 

“We were trying to protect him as much as we can with the amount of innings he's thrown before in his career to building up now,” manager Skip Schumaker said. “He's going to run right through [his career high] this year. With the All-Star break, you're trying to give him an extended amount of time to -- not heal up because he wasn't hurt at all -- but to give him just more rest.

“But it's tough to do whenever your pitcher hasn't thrown in [eight] days. Not all the time do you have your command.”

A rusty Luzardo was chased in the fifth inning of the Marlins’ 6-4 loss to the Cardinals on Monday night at Busch Stadium. Miami has dropped four in a row for the first time since May 2-6, and nine of 14 after going 23-8 in its previous 31 games.

Setting the tone is the pitching staff, which has a 5.60 ERA during this span -- 26th in the Majors.

“It has nothing to do with taking time off or anything like that, it was just more of I just felt a little out of sync with my mechanics, which again, shouldn't happen and can't happen, especially after last series,” said Luzardo, who threw during the four-day break. “I felt like I needed to come out here and pitch well for our team, and just a little frustrated that I wasn't able to do that.”

When Luzardo last took the mound on July 9, he limited the Phillies to two runs over 6 1/3 innings to secure the series win against the club chasing the Marlins in the standings. It capped a breakout first half for Luzardo, who compiled a 3.29 ERA and a 10.6 K/9 rate in a career-high 19 starts.

The 25-year-old southpaw had allowed just four runs over 31 2/3 innings (1.14 ERA) with 40 strikeouts across his last five starts, including six scoreless frames with eight K's on July 4 against these same Cardinals intending to be sellers at the Trade Deadline.

“We did a good job of shrinking the zone, and when you face an arm like that, you can't expand, because we're going to get in big trouble,” said Nolan Arenado, who hit an RBI single in the third vs. Luzardo. “So it was hard. [Luzardo] was really tough on us in Miami, and he was tough today, too, but we were able to, I guess, wait him out a little bit and find a way to score some runs.”

In Monday’s series opener, Luzardo recorded just 12 outs and needed 92 pitches to do so. Though he limited the damage to three runs (two earned), his numbers were among his worst of the season:

• 11 three-ball ball counts (most)
• 56.5% strike rate (second lowest)
• Two strikeouts (fewest since Sept. 20, 2021)
• Three walks (most since May 4)
• Four-plus innings (shortest start since June 12)

Luzardo’s 2.2 BB/9 rate in the first half was a career low, but he had difficulty gripping the ball on Monday, perhaps a byproduct of the humidity. He struggled throwing his changeup and slider for strikes.

“If those two pitches aren't working for me, then I'm basically stuck with only my fastball, and that's never somewhere we want to be,” Luzardo said. “I felt like even the fastball, I didn't have great command. It was just slipping out of my hand, and again, I feel like I just need to be able to command my breaking stuff more. That way it helps me get my fastball back in the zone.”

“He's going to be fine,” Schumaker said. “I'm looking forward to his second start after the break, and he's going to be just fine. He still had his velo, his stuff is there. I think the throwing strikes -- just like we say all the time -- when he throws strikes, he's really, really good. I think he'll fine-tune that in the next bullpen and just be fine.”