If there is anything I have learned in my brief 23 years as a Mets fan on this earth, it is that if something can go wrong, it will go wrong with a Mets team. None of that is more evident than the Mets RHP and 6’ 4” dreamboat Robert Gsellman.
Robert Gsellman was a disregarded prospect heading into the 2016 season, between the major prospect publications (Baseball America, Baseball Prospectus, MLB Pipeline, FanGraphs) only Prospectus had Gsellman in the Mets organizational Top-10, at #9.
Gsellman was called upon to step up for the Wild Card-bound Mets in 2016, one of the teams surprising storyline is the success the righty showed in the brief start in his career. The young right-hander started 8 games, producing a stunning 2.42 ERA (2.63 FIP, 3.38 xFIP) while striking out 8.46 per 9 and a healthy 54.2 GB%. When called up to the Majors Gsellman added a few mph to his fastball, dialing it up to 94 MPH while adding the devastating Warthen slider. All-in-all I used my rational Mets Fandom and screamed from the mountaintops and at anyone who would listen that Gsellman would challenge for Rookie of the Year honors in 2017.
I should have known better, I really should have.
People told me that Gsellman’s sample size of 41 innings was too small, they were very wise. But I was not the only one who believed the hype, he was one of Jeff Sullivan (of Fangraphs) darlings last off-season. Baseball Prospectus even ranked Gsellman as the 17th (!) top prospect in all of baseball.
Gsellman’s 2017 numbers were a nightmare for Mets fans. He regressed in nearly every category. He saw his ERA jump up to 5.19 supported by his 4.89 FIP and 4.79 xFIP. His K/9 decreased all the way down to 6.17 while he BB/9 increased +.14 to 3.16. He saw his GB% decrease to 49.3% while giving up more fly balls. His HR/FB was one of the huge increases in his profile jumping from 3.6% in 2016 to 14.4% in 2017.
That vaunted MPH that he gained when reaching the bigs in 2016 that scouts loved vanished, and so did the results. Gsellman had one of the league’s worst fastballs and a below average slider and curveball combination. When Gsellman did get people to chase, opponents had a 76% O-Contact percentage, the 5th worst in the league.
The real question heading into 2018 is what can Mets fans expect from Gsellman heading into the 2018 season?
Gsellman should head into Spring training competing for a back-end rotation spot with the likes of Wheeler, Lugo, and Harvey. His tail end of his 2017 was better, in the 43 innings after his return from injury he produced a 3.50 ERA but his K/9 was down all the way to 5.15, and his GB% even lower at 42.3%. His FIP (4.510 and xFIP (5.23) point to a bit of luck during this small sample size (See, I learned).
The key for Gsellman is keeping the ball down, and forcing ground balls. Throughout his Minor and Major league career he has managed keep his GB% between 50-60%. His 2017 season was the first time it dipped below 50%. The other key for Gsellman is to keep the home runs at bay. Prior to 2017, he had shown a unique ability to suppress home runs. His HR/9 in his minor league career is .4. His HR/9 in his 2016 major league stint was an unsustainable .2, but the regression closer to the mean was way higher than expected, his 2017 was 1.28. Gsellman has shown an ability throughout his professional career to keep the ball on the ground and out of the stands. For him to do that he needs to show that 70 Grade sinker that scouts believed he possessed. I would bank on Gsellman’s HR/9 and GB% moving towards his minor and major league track record.
Steamer projects Gsellman as a Mid-4 ERA pitcher in 90 innings, and I tend to agree. We very likely may see Gsellman break Spring training in a bullpen role if he fails to perform. With the recent success around the major leagues of failed starters transitioning to the bullpen, maybe Gsellman’s combination of higher velocity in shorter appearances (reaches 95-96) plus his sinker can see him carve out an important role. I personally still have a small, irrational part of me telling me that Gsellman still has the ability to be a back-end starter in the league, and I hope it is right.