Tony Gonsolin’s Struggles Attributed To Ineffective Slider

Tony Gonsolin ended the month of June on a rough note, and those struggles continued in the Los Angeles Dodgers’ 9-1 loss to the Kansas City Royals in Sunday’s rubber match at Kauffman Stadium.

Gonsolin failed to make it through the fourth inning as he retired just 10 of 21 batters faced. His final line was 3.2 innings pitched, six hits, four runs, three walks, three strikeouts and one hit by pitch.

The right-hander has now given up a combined 15 runs in just 14.1 innings pitched over his last three starts, with opponents batting .304 against him during that stretch.

Dodgers manager Dave Roberts believes Gonsolin’s recent woes stem from his slider not being effective, as seen on SportsNet LA:

“I think the thing that stands out most is he just hasn’t had his slider. Versus left, the split-change, he manages hitters and he’s been fine. With right-handers, the equalizer has been his slider. And he just hasn’t had it. It just doesn’t have the bite, it’s been up the zone and he’s not getting the swing and miss that we’re accustomed to.”

Gonsolin agreed with Roberts’ analysis but felt his slider was better against the Royals in comparison to previous starts:

“I’d say that’s a fair assessment. I thought it was a little bit better today. Some of the execution and location of it wasn’t as good, but I thought I was OK with the movement today. Just got to do better.”

Gonsolin’s slider has indeed played a major role in his struggles this season as opposing batters are hitting .250/.323/.375 with two home runs and a 103 wRC+ off the pitch. Gonsolin’s slider has registered a strikeout percentage of 24.2%, which is slightly down from 25.4% a year ago.

Furthermore, the 29-year-old is getting fewer ground balls when throwing his slider, while line drive and fly ball percentages have increased from last year. Gonsolin’s slider also has a pitch value of -1.3 this season, which is down from a career-best 9.1 last year.

Tony Gonsolin frustrated by season performance

Coming off a first career All-Star Game selection last year, Gonsolin looked to continue being a key member of the Dodgers starting rotation in 2023. However, he began the season on the 15-day injured list due to a sprained left ankle and only made one rehab start because of additional injuries.

Through 12 games this season, Gonsolin has gone a modest 4-3 with a 3.69 ERA, 4.48 FIP and 1.12 WHIP across 61 innings pitched. He has been frustrated with his performance so far but is searching for answers on how to improve.