MIAMI -- Before the July 31 Trade Deadline, there was speculation that Starlin Castro wouldn’t even still be with the Marlins. Not only did the 29-year-old infielder stay, he’s become a valuable leader and significant contributor on a young, developing squad.

Castro came up big all weekend against the National League East-leading Braves, collecting four more hits on Sunday afternoon in the Marlins’ 5-4 loss at Marlins Park.

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“Star continues to swing it. It's good to see,” Marlins manager Don Mattingly said. “No matter what the first part of the year looks like, if he's lucky or unlucky, or whatever. He can hit.”

Setting an example as a veteran presence, Castro went 11-for-18 (.611) in the four games, with two home runs and eight RBIs. Miami split the series with Atlanta.

Castro extended the ninth inning with a two-out single that advanced pinch-runner Deven Marrero to third base. But the game ended when Luke Jackson retired Harold Ramirez on a fly ball to center.

“We just continue to play as a group and help the young guys continue moving forward,” Castro said. “Continue playing hard, and pick each other up.”

Since the All-Star break, Castro is hitting .316 with five home runs, six doubles, two triples and 20 RBIs in 29 games. In the first half, he hit .245 with six homers and 34 RBIs in 88 games.

For the season, he’s now at .262 with 11 homers and 54 RBIs.

In the series finale, Castro delivered a run-scoring single off Mike Foltynewicz in a three-run first inning.

But the Braves, behind Ender Inciarte’s three-run home run off Hector Noesi, and Ronald Acuña Jr.’s solo homer in the fifth, pulled ahead, 5-4.

The fight the Marlins showed in the series caught the attention of the Braves.

“That was us a couple years ago,” Foltynewicz said. “Guys were out there grinding for hits. They're young, they're good. You see how they put the bat on the ball. It doesn't have to be a home run.

“Just spraying stuff left and right, getting hits, getting walks and getting guys on there and playing good baseball. It's tough when you don't have household names, but they absolutely want to play and make a name for themselves.”

In the sixth inning, Castro missed homering for a third straight game by inches when his long drive to left-center bounced high off the wall. Initially, it was ruled a home run, but that was overturned by a crew chief review. Instead, it went for a double. Castro later scored his second run of the game in the inning on Jorge Alfaro’s infield single.

On a team building for the future, Castro understands his role is mainly as a mentor and a mainstay for the rest of the season.

Isan Diaz, ranked by MLB Pipeline as Miami’s No. 5 prospect and 86th on the Top 100, is the second baseman of the future.

“I think it's good,” Castro said. “They're going to bring up a couple young guys. I think it's fun watching those guys coming in here and [showing] what they can do in these two months and then get ready for next season to start.”

The arrival of Diaz is why the Marlins explored the trade market for Castro. But unable to find a trade fit, Castro agreed to move to third base, where he’s been steady in the field and at the plate.

With youth comes inexperience. And in the ninth inning, Diaz made a baserunning mistake that led him being thrown out at first by Acuna in right field.

Leading off, Diaz lifted a fly ball to right field. Initially, Diaz thought it was a routine out, but Acuna -- playing deep in spacious Marlins Park in a no-doubles situation -- was unable to reach the ball. Diaz made an aggressive turn at first, and Acuna threw behind him to Freddie Freeman, who applied the tag for the out.

Miami ended up having runners on the corners with two outs before Ramirez’s game-ending fly ball to center.

“I know I was the tying run,” Diaz said. “I got jammed. I forgot they were playing no doubles. I was really trying to run the ball out. I was kind of was just a little too aggressive, and kind of just got a little far out. I thought it was going to be caught, yes.”