Analysis: What a healthy James Paxton could mean for the Mariners’ starting rotation

James Paxton and Blake Snell stood chatting near the D1 gate of Sea-Tac airport, early Monday morning, waiting to board their flight to Phoenix. Neither the mass of people waiting in the boarding area nor the swarms of snow-stranded travelers shuffling by had any idea that two of baseball’s most talented left-handed pitchers were conversing.

Then again, only diehard baseball fans might have recognized them without the required masks. And with masks? Not so much.

While they share so many similarities – left arms seemingly touched by lightning bolts, blazing fastballs, devastating breaking pitches and unhittable stuff when healthy – the juxtaposition of where they are in their careers and where they are going beyond their immediate mutual destination of the Peoria Sports Complex for COVID-19 testing is palpable.

Snell, 28, was headed to the Padres’ side of the complex as the biggest acquisition in an offseason filled with them for San Diego. When we last saw him on a mound, he was dominating the Dodgers before being prematurely pulled by Kevin Cash in Game 6 of the World Series, which the Rays would ultimately lose. With a talented young Padres team, Snell still has great seasons ahead of him with the possibility of one more big contract possibly in his future as a free agent at age 31.

Meanwhile, Paxton, 32, is returning to where it all began for him – the Mariners’ side of the complex – where much has changed in the two seasons he was gone, other than the postseason drought. It was there on March 4, 2011 when he showed up as an awkward and overwhelmed 22-year-old, having just ended a protracted holdout for a larger signing bonus after being selected in the fourth round of the 2010 draft.  A whole baseball career was still ahead of him.

Now, “Pax” is back as an established pitcher with an uncertain future. He actually isn’t officially a Mariner quite yet. He still has to take and pass the team’s extensive physical Wednesday before his 1-year, $8.5 million contract is signed and finalized.

Paxton is expected to pass the physical with the signing announced on Thursday. But the required MRIs of his surgically repaired back and left forearm/elbow should be examined closely since both were issues for him last season, limiting him to just five forgettable starts.  

In a brief preflight conversation, Paxton admitted that is a big season for him in terms of his career. He needs a bounce-back season to show people that he’s completely healthy and re-establish his value as a front of the rotation starting pitcher. Some people call them “prove-it” deals or “show-me” contracts where a player accepts a one-year deal to prove or show he’s better than the previous season, earning a multi-year deal. It worked for Adrian Beltre, Nelson Cruz and most recently Mike Moustakas and pitchers Nathan Eovaldi and Dallas Keuchel.

For Paxton, the logical choice was to come back to where he felt the most comfortable, experienced the most success and where he and wife, Katie, lived this offseason. And with Katie planning to stay and work in Bellevue during the season, returning to the Mariners made even more sense.  

When Paxton was traded to the Yankees on Nov. 19, 2018 in exchange for Justus Sheffield, Erik Swanson and Dom Thompson-Williams as part of the Mariners’ rebuilding plan, the idea he’d be back in his first year of free agency on a 1-year deal with an average salary wouldn’t compute. He was coming off a two-year stretch of dominance with Seattle where he posted a 23-11 record in 52 starts with a 3.40 ERA and 364 strikeouts in 296 1/3 innings. Paxton posted a 15-6 record with a 3.82 ERA in his first season with the Yankees. But persistent back pain in his final three outings of that season, failed rehabilitation of the issues and initial failure to identify the cause, eventually resulted in a microscopic lumbar discectomy with the removal of a peridiscal cyst in February.

The back surgery was far more debilitating than he anticipated. Even with the extra recovery time due to the COVID shutdown, his legs didn’t seem to have the same strength or endurance upon return. His inability to drive off the mound with his left leg eventually led to flexor tendon issues in his elbow. He was subconsciously using more of his arm to make up for the lost velocity from the weak legs – a bad equation. He had to re-learn his mechanics and arm slot this offseason.

If a healthy Paxton returns to his past form, benefitting from the extra day of rest in the six-man rotation, he might not get a full season in Seattle. He’d be a coveted trade value at the deadline. It would also open a spot for top pitching prospect Logan Gilbert.  

But for now, how does Paxton fit in the Mariners’ six-man rotation?

A few weeks ago, general manager Jerry Dipoto said that the rotation had spots locked up for lefties Marco Gonzales, Yusei Kikuchi, Justus Sheffield and right-hander Chris Flexen. Paxton locks up a fifth spot, leaving one spot open for competition. Right-hander Justin Dunn would figure to be the favorite over left Nick Margevicius, if for no other reason than to avoid having five lefties in a six-man rotation.

While some might feel that four lefties in a six-man rotation is too many, it’s instructive to note the noticeable differences in velocity, stuff and pitching profile among the lefties. The hesitancy to pitch lefties back-to-back in a series is diminished if they throw completely different.

Of the lefty starters, Paxton and Kikuchi have similar pitch profiles with power four-seam fastballs and wipeout sliders. Gonzales doesn’t throw over 90 mph with his fastball. He uses pinpoint command, superior preparation and ruthless execution for his consistent success. Sheffield used to consider himself a power pitcher, but now he’s moved closer to Gonzales in his use of a two-seam fastball and a willingness to pitch to contact. Margevicius is somewhere between Gonzales and Sheffield.

Realistically, the Mariners could slot their rotation this way:

1. Gonzales
2. Paxton
3. Flexen
4. Sheffield
5. Kikuchi
6. Dunn

Of course, adding another veteran right-hander, perhaps a former Mariner taking his third turn with the team, slotted at No. 3 spot, bumping Flexen into Dunn’s spot at No. 6 would make the rotation quite interesting. Like his buddy Pax this season, Taijuan Walker returned to the Mariners on a one-year prove-it deal last season, showing he was healthy and productive. Perhaps, the Mariners will show their fans adding talent to the rebuild and raise expectations this season matters more than payroll budgets, and offer Walker a “proved-it” contract.