Once the New York Mets are allowed to play baseball again — and let’s hope that eventually happens — the bullpen is going to be a crucial piece to whether they ultimately succeed or fail. That was already the case with everyone healthy and reporting to Port St. Lucie for Spring Training in February, but it’s even more true now with Noah Syndergaard on the sidelines due to Tommy John surgery.

All of the usual suspects have gotten a lot of attention from the bullpen portion of manager Luis Rojas‘ roster — guys like Edwin Diaz, Jeurys Familia, Dellin Betances, and Seth Lugo. This attention is justified because of both their past track records and projected roles.

As I mentioned last week in talking about the bullpen’s increased importance for New York in 2020, one dude I glossed over a bit (despite calling him an x-factor) was Robert Gsellman. That’s not necessarily fair, especially since the right-hander has racked up 143.2 innings as a reliever since the start of 2018 (good for the 10th-highest mark in baseball). While his overall production during this period of time doesn’t come close to what Lugo has accomplished, he’s clearly been a valuable and oft-used asset for the Mets.

With that in mind, here are three areas that are key to Gsellman’s age-26 campaign being one where he finally takes a step forward in his season-long performance.

Performance at Home

While the sample sizes aren’t exactly identical, it’s close enough to see that Gsellman was a different pitcher on the road when comparing his performance to what he did at Citi Field last year. Through 24.1 innings pitched in Flushing, he posted an 8.51 ERA with a .374 wOBA against, compared to a 2.29 ERA and .290 wOBA against through 39.1 road innings.

With just 0.37 home runs allowed per nine innings and a 7.0% walk rate at home, it’s not as if he was performing badly in every respect. He did still post a 1.77 WHIP, which was coupled with a .425 BABIP allowed and an atrocious 44.8% strand rate. When looking at his batted-ball profiles at home and on the road, it looks like he was the victim of some tough luck — the distribution of batted-ball events doesn’t appear to be drastically different, and his quality of contact was actually much better at home (22.2% soft-hit rate, 23.5% hard-hit rate) then it was on the road (21.5% soft-hit rate, 38.3% hard-hit rate).

In fact, Gsellman’s 3.21 FIP at home was head-and-shoulders better than that same number as a visiting player (4.69). It looks like the righty’s Citi Field struggles were more of an aberration that over-corrected on the road, so it’ll be interesting to see how things shake out moving forward.

Getting His Curveball Back on Track

Gsellman’s pitch mix went through a dramatic shift between 2018 and 2019, as his fastball usage went from 62.7% to 51.8% and his slider usage ticked up from 16.6% to 26.7%. What’s been consistent over the past three seasons, though, has been his curveball usage, which has stayed between 11.6% and 11.9% during that period of time.

What has changed is the performance of the pitch. Here’s how key statistics have shifted between ’18 and ’19:

For a pitch that he’s consistently leaned on over the years, this is a substantial step backward. The performance from a pitch value standpoint got worse as the year dragged on, too. In the first half, FanGaphs pegged Gsellman’s curveball as producing a value of -1.33 on a per-100-pitch basis. From the midsummer classic to his final appearance on August 11th, that number dipped even more to -5.16.

Getting this pitch back on track will only help the other pitches in his arsenal, including a slider that remained effective despite the spike in usage (1 wRC+ in ’18 to 58 wRC+ in ’19).

More Consistency with Quality of Contact

Striking out hitters at a high rate has never been part of Gsellman’s game. His career strikeout rate currently stands at 18.7%, with his yearly numbers coming in at 22.7%, 14.9%, 20.3%, and 21.7%. With these facts in mind, it’s even more important for the right-hander to control the quality of contact from opposing hitters — especially when he’s being called upon in high-leverage situations.

Here’s the month-by-month breakdown of how Gsellman’s soft-hit rate and hard-hit rate allowed fluctuated throughout 2019:

The variance in these statistics is wider in this case because of the smaller sample sizes of innings, but it also shows how much more important consistency would be here. Gsellman’s walk rate as a reliever has been above 8.0% in each of the past two seasons, while his strand rate has failed to eclipse 70.0% in either instance on a year-long basis.

A strong start to 2020 will not only be beneficial to the Mets’ bullpen, but it could also give New York options if the starting staff’s roster depth continues evaporating and they feel the need to pluck a guy like Lugo from the ‘pen to insert him into the rotation for any period of time. With a relief corps that is perceived to have more depth than last year, Gsellman’s workload may be more limited, but his importance could be just as high, if not higher.