Prospect season in review: Mariners’ Kirby

MiLB.com's Prospect Season in Review series spotlights players who shined brightest during the 2021 campaign. Here's a look at third-ranked Mariners prospect George Kirby. For more player journeys on The Road to The Show, click here.

A healthy competition among Mariners pitching prospects emerged during camp. Some from that group turned into breakout stars. Other highly touted names lived up to their reputation. George Kirby did both in 2021 -- a long-anticipated season for the club’s third-ranked prospect.

He proved his ability to be a control artist during his first taste of professional ball in 2019. Then he had one of the more intriguing transformations during that offseason and the lost pandemic year with rumors of heaters flying out of his right hand faster than 100 mph and drastic movement added to his off-speed pitches that did not sacrifice his precise control.

Kirby made just 15 starts between High-A Everett and Double-A Arkansas in 2021 after being limited by a shoulder ailment in the middle of the season. But he showed the makings of an emergent ace within a deep group of talented pitchers.

“Everybody likes to be the best,” Mariners farm director Andy McKay told MLB.com in April. “To be the best around here as a pitcher you have to keep your foot on the gas and keep pushing. There might be someone on the other field everyone’s watching. It’s exciting to have that many guys who are interesting like that and exciting to watch.

“We have that internal competition going. When you draft as much pitching as we’ve drafted, you hope it’ll look like that.”

The 23-year-old compiled a 2.53 ERA with 80 punchouts over 67 2/3 innings while opposing batters to a .227 average overall. It was the first full season for the 20th overall Draft pick in 2019. Kirby is the only player to ever be selected out of Elon University in the first round, and he built his profile largely on incredible control.

Kirby walked 50 batters in 240 total innings over three seasons with the Phoenix, and only six of those free passes came during his final 88 frames in his junior year. He followed that season with 23 innings at then-Class A Short Season Everett, where he did not walk anybody.

“I'm happy I'm able to command my pitches the way I do. I’ve got to keep working on it. I can always get better,” Kirby told MLB.com in March. “It's awesome. Just the ability to put a pitch where you want it, it's fun to be able to do that and mix it up.”

Kirby did not meet the unrealistic standard he set for himself in 2019, but he kept his walk rate low again in 2021 (5.5 percent). His 15 total walks were fewer than all but 31 pitchers to complete 60 innings in the Minors this season.

There was some evidence of the 6-foot-4, 215-pounder’s physical transformation. He was able to keep his fastball around 98 mph in games and use it effectively at the top of the zone, and there was some added depth to his sinking changeup. Kirby pairs that with a sweeping slider and downer curveball that gives him a very dangerous arsenal.

In just his second start of the season, Kirby completed five hitless innings and stuck out eight against Tri-City. Top Mariners prospect Julio Rodriguez homered in support of Kirby during that game, and the No. 33 overall prospect caught a glimpse into what could be a potentially exceptional future.

“It's just special," Kirby told MLB.com after that game. "We're grinding and we're just hoping that we can help out the big league team sometime soon."

The Rye, New York, native made seven more starts with the AquaSox, three of which were scoreless, before being shut down after his July 10 outing with what Mariners general manager called “shoulder fatigue.” Kirby returned to action on Aug. 7 and made just one more appearance before being promoted to Double-A. He left the High-A West with a 2.38 ERA and 52 strikeouts over 51 2/3 innings.

Kirby was mostly dominant after coming back from his hiatus, save for two difficult outings. Four of his final seven appearances were scoreless, including his final start of the year, in which he allowed just two hits over 5 2/3 frames against Wichita.

It was a difficult year to stand out among Mariners pitching prospects. The club’s former top pitching prospect, Logan Gilbert, threw 119 1/3 innings in his first Major League season. No. 4 Seattle prospect Emerson Hancock held a 2.62 ERA over 44 2/3 innings, and 10th-ranked Matt Brash burst onto the scene with a 2.31 ERA in 97 1/3 total frames -- both of whom accompanied Kirby in the Everett and Arkansas rotations. That’s not to mention the very respectable seasons from seven-ranked southpaw Brandon Williamson and right-handers Connor Phillips (No. 8) and Levi Stoudt (No. 9).

Seattle is obviously rich with pitching prospects, but in 2021, Kirby emerged as the veritable leader of the pack.