Instead of letting things snowball during a three-run second inning, DeSclafani retired 10 in a row en route to a career-high 6 1/3 innings in his third big-league start.
''I knew I had to rebound and throw some zeroes up,'' said DeSclafani, who struck out five and walked one. ''I just had to make quality pitches.''
It helped that his battery mate was rookie J.T. Realmuto, who caught his games in both Double-A Jacksonville and Triple-A New Orleans.
When DeSclafani returned to the dugout following the top of the second, pitching coach Chuck Hernandez and manager Mike Redmond told him to just focus on getting ahead of batters and not shying away from them.
''He's got great mound presence, he's smart, he understands, he gets it,'' Redmond said. ''I thought he and J.T. did a great job together for two young guys in a big-league start. Sometimes that can get a little bit hairy, but they've worked together before. I thought they did a great job.
''Their tempo was good, the pitch selection was good. He got in a little bit of a jam but he was able to make his pitches and get through it and he gave us exactly what we needed. For a young guy coming to the big leagues, that was a great start.''
DeSclafani worked around a double in both the fifth and sixth to avoid further damage. He was charged with his fourth earned run in the seventh when righty Sam Dyson allowed an inherited runner to score from first.
The 24-year-old took over Jacob Turner's spot in the rotation after spending a month back in the minors following his initial call-up.
''It's just something where you have to keep a consistent mentality of being aggressive,'' DeSclafani said. ''You can't go into those situations pitching scared. You've got to pitch aggressively and try to the ball in play and give your team a chance to make outs. I don't want to nibble on the corners and fall behind guys.''
The Marlins optioned left-handed reliever Dan Jennings to Triple-A New Orleans and catcher J.T. Realmuto to Double-A Jacksonville following Wednesday's 6-1 loss to the Chicago Cubs to make room for Opening Day catcher Jarrod Saltalamacchia and right-handed reliever Kevin Gregg.
Saltalamacchia will come off the 15-day disabled list to catch southpaw Andrew Heaney's major-league debut on Thursday. He has been out since June 1 with a concussion.
In two rehab games with Single-A Jupiter, Saltalamacchia went 2 for 7 (.286). He caught eight innings on Monday and was the designated hitter on Tuesday.
Gregg, who signed a minor-league deal with the club at the beginning of the month, will have his contract selected.
The 35-year-old allowed four runs (one earned) on three hits in one inning with the Hammerheads. In five outings with Triple-A New Orleans, he went 1-0 with a 3.00 ERA, finishing a pair of games.
Miami had an open spot on the 40-man roster after designating both Randy Wolf and Kevin Slowey for assignment and calling up Heaney on Monday.
Although Jennings had not allowed an earned run in his last 15 games spanning 13 frames, he had permitted eight of 13 inherited runners to score.
Realmuto was called up from the Suns when Saltalamacchia went on the DL. In seven games, he hit .200 with five RBI.
"It's good to have him back," Redmond said of Saltalamacchia. "We missed him for sure. i thought J.T. did a great job for a young guy coming up from AA. I was very impressed by his gamecalling. He got some big hits for us. He did a great job, but Salty is a guy that has been able to control our pitching staff. We need that stability and we need him and his bat in the middle of the order."
Redmond's decision to place Adeiny Hechavarria in the second spot on Tuesday went so well that he put him there again on Wednesday.
Hechavarria matched his career high with four hits, going 4 for 5 with a run. On the season, Hechavarria is 6-for-17 (.353) batting second compared to .264 from the eighth slot where he has had his most plate appearances (139).
''I've talked to you guys about him and ultimately what I envision for Hech down the road hitting second,'' Redmond said following Tuesday's game. ''I think you saw that (Tuesday) and how exciting this guy can be if he's patient at the plate and gets good pitches to hit, he can do a lot of damage and he put together some great at bats. It was fun to watch him out there.''