MIAMI -- When Seth Johnson exited his Major League debut on Sunday afternoon, he and manager Rob Thomson had a long chat in the dugout.

Johnson had been hit hard by the Marlins in the Phils’ 10-1 series-finale loss at loanDepot park, allowing nine runs on eight hits and three walks over 2 1/3 innings. Johnson became the second pitcher in AL/NL history to allow nine or more earned runs and three or more walks without any strikeouts in his MLB debut, the first since Hanson Horsey on April 27, 1912.

It wasn’t an ideal first big league start in the slightest.

“Yeah, you can say that,” Johnson said. “But nah, a really cool experience. Really happy for my family to be able to be here. Just wish it went a little bit better, but still very grateful for the opportunity. … Definitely my worst outing of the year and stuff.”

“Taking advantage of a debut today from a little bit of a control issue,” Marlins manager Skip Schumaker said. “We took our walks, commanded the zone well, and then when he came inside the strike zone, our guys took advantage of it.”

It also didn’t help that the Phillies’ offense was shut down the first time through the order by Marlins starter Edward Cabrera, and held hitless through five innings before Brandon Marsh singled in the sixth.

Johnson was making a spot start after Taijuan Walker was demoted to the bullpen and Tyler Phillips went just two-thirds of an inning on Tuesday against the Blue Jays. (The Phillies might have called on Kolby Allard, but he was optioned on Aug. 26 and unable to be recalled until Sept. 10.)

The Phils’ No. 15 prospect, per MLB Pipeline, Johnson was acquired from the Orioles in the Deadline deal that sent Gregory Soto to Baltimore. At the time, he was in Double-A. He was promoted to Triple-A Lehigh Valley on Aug. 15, where he posted a 0.56 ERA over three starts.

Johnson’s climb to the Majors has been slowed somewhat by his health; this is his first full professional season since he underwent Tommy John surgery in 2022.

But Johnson, who is with his third organization since he was selected as the No. 40 overall pick in the 2019 Draft by the Rays, is enjoying the Phils’ approach to pitching. It’s helped him simplify his game.

“I think the big [difference] is, Baltimore is very data-based, I guess,” Johnson said pregame on Saturday. “I think [Philly] is a nice blend of the numbers and like, baseball strategy and kind of old school. I've been really enjoying it so far.

“For me, it's simplified everything. Just getting good at doing basic things, basic concepts, [like] moving the fastball around, and not really worrying about pitch shapes all the time, but just going out there, trying to pitch.”

While the results might not have been there on Sunday -- and certainly, the nerves likely didn’t help -- Johnson gave Thomson and general manager Dave Dombrowski their first live look at his arsenal. Thomson liked what he saw, though there is work to be done.

“I just think he was up in the zone -- in the hitting zone,” Thomson said. “[His] stuff's OK. He might have been nervous the first couple hitters, but, you know -- the other thing is, we got to check and see if he's not giving something up [tipping pitches]. …

“A couple hitters he got behind, and then, like I said, there's -- you can pitch up, but you better pitch up up, and he wasn't getting the ball there. So, yeah, I felt bad for him.”

So, what was Thomson’s message to Johnson in the dugout after his exit?

“Just [told] him that he's got good stuff, because he does, and to keep battling -- and everybody goes through these types of things,” Thomson said. “You know, it's his first start in the big leagues and I'm sure at some point he's going to get another one. We haven't discussed who's coming back on Saturday yet. But he's gonna pitch in the big leagues again.”