Seattle Mariners Farmhand Throws Unbelievably Slow Pitch at Less Than 50 Mph!

Jhonathan Diaz, the definition of a crafty lefty.

Seattle Mariners starting pitcher Jhonathan Diaz (74) reacts to a home run hit by Chicago White Sox first baseman Andrew Vaughn (25) (not pictured) during the third inning at T-Mobile Park on June 11, 2024. | Steven Bisig-Imagn Images

The Tacoma Rainiers, the Triple-A affiliate of the Seattle Mariners won a wild 13-10 affair against El-Paso on Tuesday night, getting contributions from several familiar names, including Ben Williamson, Harry Ford and Miles Mastrobuoni.

Rainiers win 13-10 in 10!
Ben Williamson 3-6, 2B, 2R, RBI
Harry Ford 2-5, R, RBI, BB, K
Samad Taylor 2-5, R, RBI, BB, 2K
Miles Mastrobuoni 3-5, 2 2B, 2R, 3RBI, BB,SB
Leo Rivas 1-3, 3B, R, RBI, 2BB, SF, SB
Troy Taylor 1IP, 1H, 0R, 0BB, K, WIN
Michael Fulmer 1IP, 1H, 0R, 0R, 2K, SV

— Mariners Minors (@MiLBMariners) August 27, 2025

However, the best moment of the game? That just might have been a curveball from starting pitcher Jhonathan Diaz that registered less than 50 mph on the radar gun.

You can see it below:

Slow breaking ball from Jhonathan Díaz. It was at 46.9 mph. pic.twitter.com/jjRnDIMx8S

— Mariners Minors (@MiLBMariners) August 27, 2025

Well, that's certainly one way to vary up your speeds and rhythms.

A crafty lefty

Diaz certainly fits that description, doesn't he? Now 28 years old, he's appeared in parts of five major league seasons with the Los Angeles Angels and Mariners. He's gone 2-2 lifetime with a 4.66 ERA, appearing in 17 games and making seven starts. He made five appearances for the Mariners a season ago, going 0-1 with a 4.66 ERA.

He's appeared in one game this season, giving up no runs in 1.1 innings.

Seattle Mariners starting pitcher Jhonathan Diaz (74) pitches to the Chicago White Sox during the first inning at T-Mobile Park in 2024. | Steven Bisig-Imagn Images

Minor league success

Though he hasn't had much opportunity at the big-league level, Diaz has had success in the minors. This year, he's 8-6 with a 4.71 ERA at Tacoma, striking out 92 batters in 112.2 innings. He's made 23 appearances, including 22 starts.

And while the ERA seems high, he's actually in contention for the ERA crown in the hitter-friendly Pacific Coast League.

The race for the PCL ERA title is hilarious. pic.twitter.com/ZZJVcwin9y

— Mariners Minors (@MiLBMariners) August 27, 2025

Major league chances

With the M's quintet of starters now healthy at the big-league level, Diaz doesn't seem to have much of a path to a major-league role. Furthermore, Emerson Hancock, Logan Evans, and eventually Kade Anderson, would all seem to be ahead of him as depth options.

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