MIAMI -- Zack Wheeler threw 1,942 fastballs last season. Only one of those 1,942, a lonely 93.4 mph sinker on May 12, was slower than an average MLB fastball, which sits at 93.5.

In an 11-3 loss to the Marlins in Sunday's series finale at loanDepot park, Wheeler's second start of the season after not pitching in a Grapefruit League game all of Spring Training, the 2021 National League Cy Young runner-up dipped below that mark 10 times. Wheeler bottomed out at 91.1 mph, a fastball so slow he hadn't thrown one like it since April 24, 2018, and had only thrown 14 like it in his entire big league career. Only one-tenth of one percent of the 10,431 fastballs Wheeler threw from his 2013 debut through his first start of 2022 were 91.1 mph or slower.

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This was the worst start of Wheeler's Phillies career. He allowed seven earned runs on eight hits in three-plus innings -- his most earned runs allowed since he arrived in Philadelphia in 2020, and tied for his fewest outs recorded.

"When your velo's down a little bit, you've just got to pitch a little different. You can't just sneak stuff past guys like I'm used to," Wheeler said. "Hopefully that will come, as I get stronger and get my feet under me. I've just got to figure out how to pitch with that velo for right now, until it comes."

Wheeler recorded just one whiff with his four-seamer and sinker, on 20 swings. That was similar to his first start against the Mets, when he got just one fastball whiff on 14 swings. But facing the Marlins, his command also failed him. Wheeler walked three batters and hit a fourth, compared to only three strikeouts.

"Power guys, we always talk about [how] it takes a little bit longer than non-power guys, and I think he's probably feeling the effects of a really short Spring Training," manager Joe Girardi said.

Seeing the results in Miami, it certainly appears that Wheeler's lack of buildup for the season -- right shoulder soreness delayed his spring schedule, and he pitched only in intrasquad games -- is affecting his stuff.

Girardi said that when the Phillies kept Wheeler in the rotation to open the season, they knew they wouldn't be getting the normal Zack Wheeler. The team has chosen to ramp him up through actual Major League game action. Wheeler was limited to 65 pitches in his first start; he threw 66 against the Marlins. 

Though Wheeler's stat line looked fine in his first start -- 4 2/3 innings, two hits, one run -- his velocity was also down. Not as significantly as Sunday, but down.

Girardi maintained that Wheeler's arm is healthy. As far as the lost velocity, he said, "Yes, it was down a little bit, but nothing that's alarming to me."

Wheeler's average fastball velocity in his first start was 95.0 mph. Against the Marlins, it dropped to 94.1 mph. Those are his two worst single-game marks since he joined the Phillies. His previous low, 96.1 mph, was over a full mph faster than his April 12 start, and two full mph's faster than Sunday's.

Wheeler's Lowest average single-game fastball velo with Phillies
94.1 mph -- April 17, 2022 vs. Marlins
95.0 mph -- April 12, 2022 vs. Mets
96.1 mph -- June 22, 2021 vs. Nationals
96.2 mph -- Sept. 22, 2021 vs. Orioles
96.2 mph -- Aug. 5, 2020 vs. Yankees

For the season, Wheeler is averaging just 94.5 mph on his fastballs, a 2.5 mph drop from last year, when he averaged 97.0 mph, top-five among starting pitchers. 

Wheeler believes his normal velocity will come back, since he's essentially still pitching Spring Training games in the regular season.

"I think so. I think so," Wheeler said. "Hopefully that's what it is. I feel fine physically … It's kind of, go along the lines of spring. I hate saying that, just because I feel like I'm making an excuse. But I've just got to figure out how to pitch with what I have right now."

Wheeler is supposed to be an ace, and he's owned a Marlins team that gives the Phillies lots of trouble. Entering Sunday, Wheeler had a 1.77 ERA in his last 10 starts against Miami. But his rocky finale left the Phillies losers of three of four games in the series.

"He'll get there," Bryce Harper said. "He'll be where we need him to be. I'm not worried about Zack."