Very few Mariners rookies have played like Rodríguez has thus far. You’ve probably heard of them.
There were two articles I considered writing for this morning.
One was about the Seattle Mariners, and how boned they are. I’ll save you the nonexistent click – they’re pretty boned! At least for this year, being 9.0 games under .500 is a difficult hill to surmount, even if they play up to their potential the rest of the way. It’s not impossible, as the recent Braves and Nationals have shown us, and they are ostensibly just 6.0 games back of the third Wild Card spot, but they trail the division by 11.0 games. Sweeping Houston this weekend would get them back to just 8.0 games back. It’d be a shocking outcome for the weekend, but it’d be the sort of start they’d need to begin digging out of last place. But this is not that article.
This article is about Julio Rodríguez, the primary source of esprit de corps, joie de vivre, and pon de replay in Mariners-land thus far this year. His .267/.320/.406 line and 118 wRC+ in 44 games and 178 plate appearances has been a source of invigoration desperately needed given the club’s swooning performance over the past month. He’s already been worth 1.1 fWAR and 0.9 bWAR despite being the 2nd-youngest player in MLB on Opening Day behind his friend and Tampa Bay Rays SS Wander Franco. Rodríguez is just under half a year younger than fellow wunderkind Bobby Witt Jr., who has played mostly 3B for the Royals, but has almost a year and a half of youth on Tigers 1B Spencer Torkelson, as well as two years on fellow impressive rookies OF Gilberto Celestino of the Twins and C/1B/OF MJ Melendez of the Royals. Rodríguez has three years or more to go before he reaches the ages of Cleveland OF Steven Kwan, Astros SS Jeremy Peña, or Cardinals INF Brendan Donovan. In a year full of exciting rookies both expected and unexpected, Rodríguez is standing out, trailing just Peña by both WAR metrics for value thus far.
Julio’s debut made me curious about other young Mariners over the years. Through 44 games, he is already in just the 11th Seattle Mariner season in which a player collected at least 150 plate appearances in their age-21 season or before. The previous 10 were achieved by just six players, with the first three seasons of Ken Griffey Jr.’s career (1989-91), the first two for Álex Rodríguez (1996-97) and José López (2004-05, as well as the rookie campaigns of Ketel Marte (2015), Jarred Kelenic (2021), and early Mariners backstop Orlando Mercado (1983). You can see their collected totals below.
Stathead
With close to proximate time in the bigs to both of López’s first seasons as well as Mercado’s ill-fated early run, Julio is already pushing his way towards a rookie season to remember. If we look at Rodríguez’s numbers another way – combining seasons but limiting it to production during “rookie-eligible” seasons, it’s extremely plausible we may see the best debut season by a Mariners player this young since – or including – Ken Griffey Jr., particularly with the bat.
Stathead
Because of the difference in offensive environment, the raw numbers are going to compare less favorably for Rodríguez. Griffey, A-Rod, and Mercado played their home games in the Kingdome, a more welcoming environment for hitters than Safeco/T-Mobile Park for López, Marte, Kelenic, or Rodríguez. This year’s particularly juiceless baseball combined with continued improvements in pitching, even since 2015, makes for a trickier comparison without the aid of league/park/season adjusted stats like OPS+, measuring Rodríguez against his modern peers and Griffey against his own contemporaries.
In a sense, this is blatantly a numbers trick. There is no magic switch that flips the moment a player is no longer a “rookie” that impels different production or decision making. The age-based comparison is a key one as well, as both physical and mental development are still happening at a significant pace for many players at this age, and judging the success of a 19-year-old and a 26-year-old at the same level is an exercise in Scouting 101 – projecting development against a more static set of skills. But the trick goes both ways. A-Rod was a beneficiary of not just the natural development of his body and mind from his age-18 struggles to his age-20 domination, he also was afforded the opportunity to face the level of competition he needed to overcome and spend two years practicing and training to defeat it. Similarly, while Griffey excelled from the jump, he managed to take another leap in year two, and again in year three, building himself physically to some degree, but even more-so developing himself against the competition he grew more familiar with.
This is the trajectory the Mariners dream of for Julio Rodríguez. One of continued improvement, a pattern he’s shown in the minors and delivered on already even in the majors. It is a staggeringly difficult task to undertake, but we are witnessing the brilliant beginning of a career that will define the next decade of the Seattle Mariners. Even as everything else has gone mighty wrong, Julio has given reason to believe the next few years can still go right.