Jackie Robinson won the first Rookie of the Year Award in 1947. Forty years later, it was renamed to honor the Civil Rights trailblazer. Colorado may have developed many talented All-Stars during their time, but starting pitcher Jason Jennings is the only player to ever earn the prestigious award.

Jason Jennings Award for Rookie of the Year

Lucas Gilbreath

A total of 14 players suited up in purple this season with rookie eligibility, a median number in the 29 years of the franchise. 

None of those players are named Brendan Rodgers, despite the fact that the 25-year-old had yet to exceed 130 at-bats prior to 2021; however, he spent more than 45 days on the active roster between 2019-20 and thus, he was ineligible for this award. 

Of that group of eligible rookies, only six appeared in 30 or more games: three fielders and three pitchers, all relievers.

Yonathan Daza (0.5) and Dom Nuñez (0.5) were in the top 25 of National League rookies in FanGraphs’ Wins Above Replacement, and relievers Jordan Sheffield (0.2) and Ben Bowden (0.0) held their own in limited bullpen roles.

It may come as a surprise to know that one of the most emerging players for the Colorado Rockies this season – Connor Joe, who had the highest fWAR (1.4) of rookies and ranked among the top 15 in the NL – is not the obvious choice. 

The reason for that is down to the recent historical significance of the last man in the group. All the way from the A-ball and residing back in his hometown of Westminster, CO, Lucas Gilbreath is the winner of the 2021 Jason Jennings Award for Rookie of the Year. 

Besides being the rookie with the most unlikely of odds to contribute to the team in this fashion, Gilbreath provided the Rockies with something missing since the triumvirate of Chris Rusin, Jake McGee and Mike Dunn in 2017: a competitive left-handed option in the bullpen. 

Since that trio led Colorado back to the postseason in 2017 for the first time in nearly a decade, the team has struggled to put trust in any lefty reliever over the last four seasons.

Even in the playoff year of 2018, the most consistent southpaw was rookie Harrison Musgrave and his 4.63 ERA. It wasn’t much better for McGee in 2019 (4.35 ERA), and the duo of James Pazos and Phillip Diehl combined to appear in just 12 games during 2020, leaving manager Bud Black without any feasible options whenever a left-handed bat with thump stepped toward the plate.

Last time anyone checked on Gilbreath, he was a starting pitcher for the Lancaster JetHawks of the California League in 2019. Since then, the Legacy High School product became a reliever, the league was renamed High-A West and Lancaster was dropped from affiliated baseball, folding operations entirely in March 2021.

His Major League debut on May 1 saw the 2017 7th Round Pick give up a home run during an inning of work, and his first appearance at Coors Field three days later was also plagued by the long ball. Through his first 18 games, Gilbreath had a 7.98 ERA and just 14 strikeouts to go along with 10 walks in 14.2 innings pitched.

At some point in the eight days rest, which was aided by the All-Star break, Gilbreath became one of the best left-handed relievers in all of baseball. From July 17 until the final game on October 3, only veteran Aaron Loup of the New York Mets’ had a better ERA (0.33) than Gilbreath (0.69) amongst NL relievers with as many innings pitched. 

He also did a great job stranding runners 93.2% of the time. He suppressed home runs (3.8% home run to fly ball percentage) and gave up only one during the second half, limiting hard contact to 25.8% of the time. He also earned his first career save, a one-inning outing against the Dodgers in Los Angeles on July 23. 

Gilbreath was just the seventh left-handed Rockies’ rookie reliever – sorry, there’s no other way – to throw 40 or more innings joining Musgrave, Rex Brothers, Matt Reynolds, Brian Fuentes, Javier López and Roberto Ramírez. 

Of that group, only Fuentes (182) and Brothers (159) bested Gilbreath (142) in terms of ERA+. Not bad company. Fuentes was a four-time All-Star and Brothers is still active, having wrapped up his second season with the Chicago Cubs while the oft-overlooked López pitched for 14 seasons and won four World Series.

Even when looking around MLB for other left-handed relievers, Gilbreath matches up well. Of the 50 with at least 40 innings pitched, Gilbreath’s 142 ERA+ is 12th-best and his OPS+ against (69) is 13th-best. Possibly most promising of all: he’s the fourth youngest player of the bunch. 

The life cycle of a reliever has about as many stages as a butterfly and though there’s no guarantee Gilbreath will become a 24-year vet like Jesse Orosco or a six-year member of the Rockies like Matt Belisle, let alone a future closer, the odds of Gilbreath emerging from the chrysalis and taking his full form are quite promising after 2021.