Marco Gonzales Mariners

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Lately, I’ve been mulling over a handful of free agent signings that occurred prior to the MLB lockout. Specifically, ones involving left-handed starting pitchers. For me, these deals are a subtle reminder of how valuable Marco Gonzales is to the Seattle Mariners.

Perhaps that sounds like hyperbole to some of you. After all, one of the southpaws joining a new club this offseason is Robbie Ray, who signed with the Mariners. The 2021 AL Cy Young Award winner undoubtedly raises the ceiling of the starting rotation. Having said that, my initial comment isn’t an emotional exaggeration.

Yes, the hard-throwing Ray’s average pitch velocity is nearly 8-MPH faster than Gonzales’. Plus, the newest Mariner is a strikeout machine specializing in missing bats. On the other hand, Gonzales strikes out hitters at a rate much lower than the league average. And let’s not overlook last season.

Ray had a career-year, which is why he’s the reigning AL Cy Young Award winner. Conversely, the first half of Gonzales’ 2021 season was one of the worst in MLB and included a month-long IL stint with a flexor strain. Still, once we expand our view of the pair, similarities begin to emerge.

Marco & Robbie

Ray undoubtedly had the better 2021. But it’s worth noting that Gonzales pivoted from a forgettable first half to help lead the Mariners to the brink of the postseason and the team’s first 90-win season since 2003. And that’s where we first begin to see statistical parallels between our Seattle southpaws.

Gonzales had a 2.70 ERA in the second half of the 2021 season, which was relatively the same as Ray’s (2.53). Furthermore, opposing hitters had a .639 OPS against Marco compared to a .644 OPS when facing Ray. Again, virtually identical. But there’s more to consider.

Let’s compare Gonzales and Ray since the beginning of the 2018 season when Gonzales permanently joined Seattle’s rotation. The larger sample size highlights that there are multiple similarities. We also see categories where Seattle’s 2021 Opening Day starter had an edge over his new rotation-mate.

Marco & Robbie Have Similar Stat Lines Since 2018

It’s not difficult to make a case that Gonzales is every bit the pitcher Ray has been since Opening Day 2018. Perhaps even better. The Gonzaga product averaged more innings/start, while allowing fewer base runners and damaging contact less often. On top of that, an advanced metric suggests Gonzales was more valuable than Ray over the last four seasons.

Whether you prefer the Baseball Reference version of wins above replacement (bWAR) or the one produced by FanGraphs (fWAR), Gonzales delivered greater value to the Mariners since 2018 than Ray was to the two clubs he played for during that span – the Diamondbacks and Blue Jays.

Perhaps the most significant difference between Gonzales and Ray is the length and terms of their current contracts with the Mariners. Spoiler alert: there are huge disparities.

According to Spotrac, Gonzales is under contract through 2024 thanks to a four-year/$30 million extension signed with Seattle. The team also holds a $15 million option for the 2025 campaign. Meanwhile, Ray’s five-year/$115 million deal includes an opt-out the he can exercise after the 2024 season. At that time, he’ll have to choose whether to stay under contract with the Mariners, negotiate a new contract with the team, or re-enter free agency.

Like I said, huge disparities.

Some of you may suggest that Ray is making substantially more than Gonzales because he hit free agency just after winning a Cy Young Award. Absolutely true. Still, his new deal is also a reflection of the value teams are placing on quality starting pitching in the current marketplace.

It’s that market value, which helps underscore Gonzales’ importance to the Mariners. To see what I mean, let’s contrast the Fort Collins, Colorado native to Ray and other noteworthy free agent lefty starters signed this offseason.

Comparing Southpaws

The following illustrates the stats of Gonzales, Ray, Eduardo Rodríguez, Rich Hill, Andrew Heaney, Alex Wood, and Steven Matz since the beginning of the 2018 season. It’s not a comprehensive comparison and only includes a few metrics I commonly share with you. But you can see Gonzales’ production numbers put him in good standing with the names listed below.

Marco Gonzales vs Southpaw Free Agent Starters*
Eduardo Rodríguez
Marco Gonzales
Robbie Ray
Steven Matz
Rich Hill
Andrew Heaney
Alex Wood
*Sorted by bWAR

Despite being on par with this gaggle of crafty lefties, Gonzales will be making significantly less money this year than all but one of these starters. The lone exception is Rich Hill, who turns 42-years-old in March.

2022 Base Salaries
Robbie Ray ($21 million)
Eduardo Rodríguez ($14 million)
Alex Wood ($12.5 million)
Andrew Heaney ($8.5 million)
Steven Matz ($8 million)
Marco Gonzales ($5.5 million)

Source: Spotrac

Obviously, there are many factors that impacts a player’s leverage at the negotiating table and ultimately their salary. Most of them are out of their control. Putting that aside, based on his performance since 2018, Gonzales’ contract represents a momentous bargain for the Mariners.

We’ve established that Gonzales’ production since 2018 puts him on the same level as noteworthy lefties from the current free agent class. Most of whom are making considerably more money than him in 2022. But there are several other factors I’d like to discuss that further emphasize the importance of the the 19th overall pick of the 2013 draft to a franchise attempting to break its decades-long postseason drought this year.


The preceding table reveals a wide range of games started (GS) by Gonzales and our free agent starters. Rodríguez missed the 2020 season due to COVID-19 complications. But he’s been relatively healthy other than several lower leg injuries. That said, Hill, Heaney, Matz, and Wood have each had multiple IL stints due to a series of injuries, including arm-related issues. Meanwhile, Gonzales and Ray have remained relatively unscathed in that regard.

Although we intuitively realize that being there for the team is critical, it’s still worth reiterating that Gonzales and Ray have been more available than the vast majority of their peers. Only 15 starters have made more starts than Ray’s 100 since Opening Day 2018 with Gonzales taking the ball one less time.

Going The Distance

When it comes to remaining in games, Gonzales staying power is unmatched compared to the arms we’ve been discussing. Since 2018, he’s finished the seventh inning 27 times.

Seven-Plus Inning Starts (2018-21)
Marco Gonzales (27)
Andrew Heaney (17)
Eduardo Rodríguez (11)
Robbie Ray (10)
Rich Hill (8)
Steven Matz (7)
Alex Wood (6)

It turns out that Gonzales fares well when compared to all of MLB over the last four seasons, not just the left-handed free agent class. Only 14 starters have completed the seventh frame more often the 29-year-old has. That said, three-time Cy Young winner Clayton Kershaw (28) is the only left-hander ahead of him on that list.

To be fair, how long starters are allowed to go in this era varies greatly depending on the philosophy of their club. In reality, going deep into games doesn’t happen as often as it did back in the day. Therefore, we shouldn’t judge pitchers too harshly just because they don’t pitch through the seventh inning more frequently. Still, a starting pitcher capable of regularly going late into games helps relieve the pressure facing the bullpen. This matters for teams during an arduous six-month season.

Bulldog On The Mound

Since 2018, Gonzales essentially has the same number of seven-plus innings starts as Kershaw – a future Hall of Famer. This is no surprise to Mariners fans, who’ve become accustomed to his fiercely competitive nature. Despite not having an overpowering fastball, he consistently ranks well among peers when the pressure is on. You can get a sense of that tenacity by reviewing how hitters have performed against him with runners in scoring position (RISP) and where his numbers ranked against pitchers facing 400-plus hitter with RISP.

Marco Gonzales' Stats & Rankings w/RISP (2018-21)

At the risk of belaboring the point about Gonzales’ influence on the outcome of games he starts for the Mariners, there’s one more number I’d like to share with you.

Per Baseball Reference, Gonzales’ 4.2 Win Probability Added (WPA) since 2018 ranked 23rd among starters. For context, Ray’s 2.6 WPA comes in at number-43. For those unfamiliar with the metric, WPA attempts to capture a hitter’s or pitcher’s impact on his team’s win expectancy in games he plays in. If you’d like to know more about this stat, David Appelman, creator of FanGraphs, provided a helpful explanation with additional links discussing WPA here.


Since coming over in the deal sending Tyler O’Neill to the Cardinals during the 2017 season, Gonzales has ascended to become the leader of the Mariners’ rotation. That’s unlikely to change anytime soon – at least that’s how I see it.

Sure, Ray deservedly grabbed the spotlight when he signed in November and projects to take over the starting staff’s number-one spot. There’s also a wave of dynamic young arms projected to reach Seattle soon with Logan Gilbert already entrenched in the rotation. And let’s not overlook Chris Flexen, who had a breakout 2021 campaign. Still, Gonzales is the lone Seattle starter with a record of sustained superior performance.

Gonzales not only rates extremely well when compared to left-handed starters from the current free agent class. He’s consistently been top-30 among his peers dating back to 2018. All of that excellence has come at a bargain price. Yeah, Marco isn’t going anywhere.

The more I think about it, Marco Gonzales deserves a pay raise.

My Oh My…

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Luke Arkins

Luke is a native New Yorker, who grew up as a Mets fan. After the US Navy moved him to the Pacific Northwest in 2009, he decided to make Seattle his home. In 2014, Luke joined the Prospect Insider team. During baseball season, he can often be found observing the local team at T-Mobile Park. You can follow Luke on Twitter @luke_arkins

1 Comment

  1. Right on the money. Marco is undervalued because he’s not a flamethrowing strikeout machine. I seem to remember a guy named Greg Maddux who wasn’t a high octane guy but just knew how to pitch and be consistent. That’s Marco.

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