Marlins manager Don Mattingly preaches doing the little things because they can decide a ballgame. His club was unable to follow through in four pivotal instances in a 4-2 loss to the Cardinals on Monday night at Busch Stadium.

Playing short
With José Devers landing on the injured list and Corey Dickerson (foot) unavailable, the Marlins fielded a two-player bench of Lewin Díaz and Sandy León. This less-than-ideal situation has come up several times this season. It cost Miami in the seventh with a runner at first in a tied ballgame, as Mattingly pinch-hit with reliever John Curtiss. He was unable to execute the bunt and struck out.

According to Mattingly, the Marlins will know more Tuesday concerning Dickerson’s status. Rather than select the contract of infielder Deven Marrero, Miami elected to call up right-hander Luís Madero and roll with 10 relievers.

“That’s one you wrestle with,” Mattingly said of going with Curtiss. “Lewin's obviously not a great matchup in that scenario. Am I willing to use my last catcher right there? It's one of those looking back, I really wish I would have in some way either kept him in the game and been able to pinch-hit Lewin later in [Jorge Alfaro’s] spot, or just go straight up there.

“When you've got two guys sitting there and you know that's all the players you have, and one of them is your backup catcher, it's one of those in the seventh in a tie game that you're not feeling great about that. You really try to play for one run there and get the bunt down, and get [Jon Berti] a chance to drive in a run.”

Caught napping
As Curtiss bunted through strike three, Isan Díaz strayed too far off first base. Catcher Yadier Molina fired over to second baseman Edmundo Sosa, who was covering the bag with Paul Goldschmidt charging to guard the bunt, and applied the tag for the final out of the frame.

It marked the MLB-leading 13th time the Marlins have been picked off. Díaz has a club-high-tying three.

"What a heads-up play by Yadi,” Cardinals manager Mike Shildt said. “Great job by Sosa. Guy bunts through, it's a good time for a back pick. First baseman charges and Sosa saw it and was there, and of course Yadi does what he does. It was a winning play by both players."

Close call goes the other way
In the second, Adam Duvall tried scoring from first on Magneuris Sierra's double to right-center. Molina couldn't hold onto the ball, but Duvall didn't touch home. When he went back, Molina tagged him. A replay review upheld the call.

“It was a bang-bang, play, and I didn't have much room to get in there, but the first time I thought I got in there,” Duvall said. “It's always OK to go back and make sure, and that's what I was trying to do on the second attempt. I explained that to the umpire. I said I wasn't going back because I thought I missed it, I was going back just to make sure, and it never would hurt to touch it twice.”

Missing the zone
The Marlins made strike throwers a priority when revamping their bullpen over the offseason. Dylan Floro fit that bill, with 2.7 walks per nine innings in his career. He issued a free pass in just three of his first 20 outings, but he has walked at least one batter in six of his last 11. Of those six appearances, he has given up a run in half of them.

Floro walked the leadoff batter Dylan Carlson before Goldschmidt singled to put two men on. Following a Nolan Arenado flyout, Tyler O'Neill produced an RBI double that put the Cardinals ahead. An intentional walk to load the bases then set up Paul DeJong's RBI dribbler that extended the lead to two.

Entering Monday, Floro had 3.3 walks per nine innings, which would be a career high. Perhaps he’s not as sharp because of his usage; only three MLB pitchers have appeared in more games than Floro (31) this season.

"I do think the walk tonight hurts him,” Mattingly said. “You don't want to walk anybody in front of Goldschmidt and Arenado and kind of run into the middle of their lineup. Feel like the ball's coming out of his hand good and trying to make pitches. Something I'm sure [pitching coach Mel Stottlemyre Jr.’s] talking about. We've been pushing guys hard, honestly. We've had to. It seems like we're in a stretch of time where our back-end guys are in a lot of games. When you do that, you're usually probably not getting the very best version of everyone."