Mariners Starting Rotation: What to look for with Gonzales and Flexen in 2022

Feb 26, 2022, 1:40 PM
Mariners Chris Flexen...
Chris Flexen of the Seattle Mariners pitches during the second inning against the Arizona Diamondbacks at T-Mobile Park. (Steph Chambers/Getty Images)
(Steph Chambers/Getty Images)

While one of the most anticipated seasons in Mariners history is on hold until the MLB lockout ends, we’re not letting that get in our way of breaking down why 2022 should be a big year for baseball in Seattle. Keep your eye on for a series of articles looking at important topics for the Mariners. In the coming days, we will be focusing on the starting rotation.

In this post,’s Brandon Gustafson looks at Chris Flexen and Marco Gonzales.

We’re all anxious and excited to see what the Mariners will do to bolster the lineup once the lockout ends, but they’re set to enter the so-called “next phase” of the offseason with a pretty strong starting rotation.

Jake & Stacy’s Mariners wishlists for the 2022 spring and summer

After experimenting with a six-man turn the last two seasons, Seattle is set to stick with the traditional five-man rotation in 2022, and so far, four of those slots are penned in.

The headliner is, of course, Robbie Ray, the reigning American League Cy Young Award winner who comes to Seattle on a very lucrative deal after his career year with the Toronto Blue Jay in the AL East.

There’s also Logan Gilbert, the former top prospect who pitched very well for the Mariners as a rookie in 2021, especially down the stretch.

And then there are Chris Flexen and Marco Gonzales, both of whom are very much bulldogs, gamers, fierce competitors and so on and so forth.

Flexen was the glue of the Mariners’ rotation in 2021 – a role Gonzales has typically held down the last few years – after pitching in Korea in 2020.

Gonzales had his struggles early before landing on the injured list, but he, like Gilbert, finished the year exceptionally strong as the Mariners fought for a playoff spot.

The 2021 season was overall bright for that duo, but what might 2022 hold? And what can we learn from the two when taking a deeper look into their numbers – both standard and advanced?

Well, let’s dive in, shall we?

Chris Flexen: A regress or sustain candidate? 

We’ve talked a bit about breakout Mariners candidates on this site recently (you can read my pick here). I bring that up because Flexen, 27, was absolutely a breakout star for Seattle and his emergence came out of nowhere.

As mentioned, Flexen spent the 2020 season in Korea. That was after three lackluster years in the big leagues with the New York Mets.

In 27 games (11 starts) for the Mets between 2017 and 2019, Flexen went 3-11 with an 8.07 ERA, 2.132 WHIP, 6.92 FIP and walked more batters (54) than he struck out (49) in 68 innings.

But after posting a 3.01 ERA in 116 1/3 innings in Korea, Flexen signed with the Mariners on a two-year, $4.75 million deal with a club option for a third. So far, that deal is looking like quite the steal for Seattle.

All Flexen did upon returning to MLB was go 14-6 with a 3.61 ERA, 1.25 WHIP, 3.89 FIP and 125 strikeouts to 40 walks while leading the Mariners with 179 2/3 innings in 31 starts. Flexen was tied for 31st in pitching WAR in all of baseball according to ESPN.

Flexen isn’t the flashiest guy as he sits in the low-90s with his fastball, but he utilizes a four-pitch mix and generated a lot of ground balls (42.3%) while pounding the strike zone.

Per Statcast, Flexen’s walk rate was in the 89th percentile. And while he struggled to miss bats (fifth percentile whiff rate), he posted a 57th percentile in chase rate while avoiding barrels (72nd percentile barrel rate).

So why do I wonder if Flexen may be a regression candidate?

Flexen posted a solid hard hit percentage, ranking in the 56th percentile, but he was in the bottom third of the league in average exit velocity (88.9 mph) and his expected numbers were worse than his actual numbers in some notable categories.

Flexen had a 3.61 ERA, .261 opponent batting average and .414 opponent slugging percentage, but his expected ERA was 4.27, expected batting average was .268 and expected slugging percentage was .427. So they were close, but just slightly worse.

And again, he didn’t miss many bats with a fifth percentile whiff rate and a ninth percentile strikeout rate.

While some regression may be in order, that doesn’t mean I expect Flexen to pitch poorly by any means.

What Flexen gives the Mariners every time he takes the ball is a high-percentage chance to work six innings while allowing three or fewer runs, otherwise known as a quality start. Does he offer the Mariners the high upside of a purely dominant performance like Ray is expected to? No.

But if Flexen’s actual numbers in 2022 are what his 2021 expected numbers were – 4.27 ERA, .268 opponent batting average – as a mid-rotation starter? You’re absolutely taking that. Any good team will gladly take a low-4 ERA as a mid- to back-end starter. And thanks to the addition of Ray, Flexen can now be one of the better mid- to back-end starters in baseball as the Mariners’ rotation lengthens out. Plus, Gilbert and other young highly-touted arms should be establishing themselves next year, too.

Pitch to watch: Changeup

Flexen was one of the better starters in baseball when it came to mixing up his pitches.

He used his fastball 40% of the time, followed by a cutter at 29.4% and then the changeup and curveball each at 15.3%.

While the changeup was tied for the least-used pitch, it was really Flexen’s best offering when looking at what opponents did against it. That was also the case during his previous MLB tenure.

Opponents hit just .160 off Flexen’s change with a .269 slugging percentage with five extra-base hits in 2021. Additionally, Flexen generated far more swings and misses with his changeup (26.5%) than his other three offerings.

The expected numbers off the change were worse, but still very good, with an expected batting average of .199 and expected slugging percentage of .307.

What will be interesting to see is if Flexen opts to use the pitch more against right-handed hitters.

As is the case with most pitchers, Flexen used his changeup to get opposite-handed hitters – in his case, lefties – out. He threw 347 changeups to lefties compared to just 84 to righties. Meanwhile, he used all four pitches often against lefties but essentially scratched the changeup against righties.

Not every pitcher is able to be effective throwing a changeup or splitter to opponents on the same side as them, but given how effective Flexen’s changeup has been, it’s worth watching.

Marco Gonzales: Did strong finish show a 2020 repeat is possible?

Simply put, Marco Gonzales was one of the best pitchers in baseball in the shortened 2020 season.

In 11 starts, Gonzales went 7-2 with a 3.10 ERA, 0.974 WHIP, 3.32 FIP and 64 strikeouts to just seven walks in 69 2/3 innings. He also led baseball in strikeouts per walk (9.14 and walks per 9 innings 9 (0.9).

Naturally, we were all excited to see what Gonzales would do to follow up on that, especially with 2021 being a full 162-game season.

Well, 2021 started rough for Gonzales, who went 1-5 with a 5.88 ERA and 49 strikeouts to 21 walks in his first 11 starts, in which he compiled 56 2/3 innings. Gonzales landed on the injured list after his first five starts due to a forearm strain.

But over his final 14 starts, Gonzales was, again, one of baseball’s best starters.

Gonzales went 9-1 with a 2.70 ERA and 59 strikeouts to 21 walks in his final 14 starts, in which he threw 86 2/3 innings.

Overall in 2021, Gonzales went 10-6 with a 3.96 ERA, 1.165 WHIP, 5.28 FIP and 108 strikeouts to 42 walks in 143 1/3 innings. His strikeouts per walk dipped to 2.57 in 2021 as did his and walks per 9 innings with 2.6.

Gonzales’ overall numbers were pretty on par with his 2018 and 2019 seasons, where he had ERAs of 4.00 and 3.99, respectively. He did have slightly better walk rates those two years compared to 2021, however.

Per Statcast, Gonzales’ barrel rate jumped from 8.4 to 11.4 from 2020 to 2021, which was the highest of his career since his rookie season. His average exit velocity also increased from 86.6 mph to 88.1, and Gonzales’ expected ERA was 5.05, more than a full point higher than his actual ERA.

Gonzales did do a fairly good job of limiting hard contact as he ranked in the 66th and 64th percentiles in average exit velocity and hard hit percentage, respectively.

While it’s more likely going forward that Gonzales is the pitcher we saw in 2018 and 2019 than in 2020, his strong finish to the 2021 season should be very exciting for Mariners fans.

With Ray leading the rotation now, Gonzales is now more of a mid-rotation piece rather than the staff’s No. 1 guy. But he’s now one of the better and more proven mid-rotation starters in baseball and is someone who absolutely gives the Mariners a chance to win each and every time he toes the rubber.

Pitch to watch: Cutter

Gonzales used his sinker over 45% of the time in 2021, followed by his changeup (20.1%), curve (15.4%), cutter (14.1%) and 4-seam fastball (5.1%).

That order is notable because his changeup returned to his second-most used offering in 2021 after the cutter took that distinction in 2020. Gonzales’ changeup has been his second-most used pitch every year of his MLB career besides 2020.

Gonzales has always been known for having a good changeup, but a big reason he was as successful as he was in 2020 was because of his cutter, which he used nearly a quarter of the time that year.

In 2020, opponents hit just .191 with a slugging percentage of .392 off Gonzales’ cutter. Those numbers jumped to .291 and .499 in 2021.

Now, it stands to reason that Gonzales was maybe a tad lucky with the cutter in 2020 as his expected batting average and slugging percentage were .237 and .507, respectively (the 2021 expected numbers were .274 and .516 in 2021), but he missed more bats with the cutter in 2020 (21.4% whiff rate) than in 2021 (15.7%) as well.

Gonzales isn’t a swing-and-miss pitcher by any means, but the cutter was a good way for him to miss bats and barrels in 2020. If he can get that pitch going again after a tough 2021 season, perhaps Gonzales’ 2022 numbers can be closer to his 2020 stats than expected.

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