SF Giants: LHP Sean Manaea showed elite potential in season debut

SF Giants lefty Sean Manaea may have allowed three runs in his season debut, but Mikey Ajeto saw elite potential in his pitch arsenal.

The SF Giants walloped the White Sox on Monday thanks to Anthony DeSclafani being very good, and Michael Kopech being extremely not good. After DeSclafani’s six scoreless inning, though, Giants manager Gabe Kapler turned to southpaw Sean Manaea to serve as the bridge to the ninth. Manaea struggled with command throughout his outing, surrendering three earned runs over two innings, with two walks and a strikeout. That, objectively, is a fairly poor line, but as far as I’m concerned, Manaea looked like the best version of himself we’ve ever seen.

I won’t waste any time. Manaea is throwing hard. He just threw harder than any single pitch he’s ever thrown. And more importantly, he’s also sitting at a much higher velocity than ever too. Consider his average fastball velocity, by game, since 2020:

Brooks Baseball

That little blip, towards the right of the graphic? That’s his velocity from Monday, at 95.5 mph. Manaea’s first pitch of the game was a slider, called for a ball. From there, he didn’t mess around, throwing seven consecutive fastballs, ranging from 94.9 to 96.4 mph. That’s not the Manaea we’re accustomed to, but maybe the Manaea we ought to get used to.

This is the first time this season he’s been stationed in front of instrumentation that will give us pitch data. He reported sitting between 93 and 96 mph during spring training, well up from the 88 to 90 mph he was at last spring. There was no reason not to believe him then, and no reason not to believe him now. It’s not like he’s never pitched with adrenaline, and he’s only a handful of months removed from having pitched in relief.

When I think about what Manaea can be, I often think back to a start of his I wrote about against the Yankees in 2021. He induced 20 whiffs with his two-seamer alone, which he converted into 11 strikeouts, all on his two-seamer. It wasn’t an accident. That was the hardest he’d averaged on his fastball to date, the lowest his vertical release point had been, and the second-highest his average vertical fastball location had been. That should cue you in on the recipe for Manaea’s fastball. When he can throw his fastball hard at the top of the zone from a low release, it creates a flat vertical approach angle to the plate that opposing hitters struggle with.

Monday, Manaea appeared to throw all four seamers. See for yourself. First, by horizontal and short-form vertical movement:

Brooks Baseball

And then by velocity and horizontal movement:

Brooks Baseball

It’s not always easy to tell which fastball is which with Manaea. It wasn’t until last year that his Pitch Info data was cleaned up and his four-seam and two-seam fastballs were differentiated. If it is, indeed, the case that he’s throwing more four-seamers, it would make sense. He might continue to mix in the two-seamer, but if he’s looking for whiffs, the four-seamer is going to be the pitch. With this velo, with this arm slot, it’s going to create a flat approach, and given he throws from one of the widest angles of left-handed starting pitchers, that ought to miss plenty of bats, even if it didn’t today.

There’s also his secondaries. One of the emphases of the offseason was upping his fastball velocity, and clearly, he’s done that. Another, though, is getting his changeup back. I wrote in December that one of the reasons he struggled so much in 2022 that he didn’t quite have his changeup. Giants Baseball Insider's own JD Salazar had a similar analysis following his signing.

He started the offseason trying to add more run to it, but after signing with the Giants, they encouraged him to focus more on finding the depth that he’s been losing over the past few years. Consider that a success – he averaged 1.3 inches of “ride”, down from his 3.2 average in 2022 – and at 86 mph, no less.

Higher velo means a flatter approach, but now with more depth on his changeup, and perhaps a touch more on his slider, too. Between the two, he’s increased the movement differential between his fastball and secondaries, in part by reshaping them, and in part by just…not throwing his two-seamer.

Perhaps the comp here is Andrew Heaney, with better velo, and a better changeup. Or maybe the comp is Robbie Ray, with, uh, a, changeup. Either way, I tend to think those are flattering comps, especially given that he’s historically not had the home run problem that they have.

I’m not certain what the Giants intend on doing with Manaea. They’d predetermined that they’d get him some work today out of a piggyback role, but they hardly sound wedded to him as a relief pitcher. As far as I’m concerned, Manaea should play as a starter. He was sitting right at 93 mph by the end of his two-inning outing, and that’s still harder than he ever averages. Regardless of how the SF Giants end up using him, this new-look Sean Manaea is the most compelling he’s ever been, results be damned.