D-backs Rookie Starters Have Stepped Up When Needed Most

For much of the 2023 season, the Diamondbacks have struggled to field a healthy and consistent starting rotation. A combination of poor performances and injuries had depleted the organization's rotation depth by July, forcing them to get more creative in how they bridged gaps in the rotation. Zac Gallen, a frontrunner for the Cy Young Award, has been the only member of the Opening Day starting rotation who has been healthy and able for the entire season. In recent weeks the rotation has begun to show signs of improvement, and much of it is due to the recent quality starts by Slade Cecconi and Brandon Pfaadt.

"They're both up and coming pitchers for us" said D-backs manager Torey Lovullo. "They're understudies right now for Zac and Merrill [Kelly]. They're applying all their concepts and helping us win baseball games. To me, that's the reason we are where we are."

Developing a starting pitcher at the big league level can be tricky. Sometimes they can hit the ground running and pitch well out of the gate, more often it's a struggle and changes are necessary to stick. Pfaadt serves as an example of the latter, as he pitched to a 9.82 ERA in his first six starts. His fastball doesn't offer a lot of movement, with 15.3 inches of vertical break and 6.3 inches of horizontal break being below average compared to other fastballs of similar velocity and spin.

After sending him down a second time, they moved him to the far first base side of the rubber. Here's pitching coach Brent Strom's reasoning for the move:

"When you don't have the carry like you have with Ryne Nelson, who is at 20 [inches] or plus, or [Zac] Gallen when he's right at 20-plus and it has spin efficiency. Then what your next tact is to try to increase the speed of the pitch, not physically increase the speed, but increase the speed to the hitter's perception. That happens by running balls in closer to the body."

While it hasn't changed the results on his fastball much, it has made a huge difference for his sweeper. Since the change opponents are hitting .074 while slugging .093 against Pfaadt's sweeper, a stark change to the .214 and .500 marks over his first six starts.

"We're trying to keep everything condensed, and it just worked well for him" said Strom. "He's throwing more balls up and in, which causes hitters to speed up. The whole process here is to upset timing, speed people up, slow them down, and then get chases out of the strike zone. Those have been our two main focuses."

The results of that process have yielded very good. Pfaadt has a 29.4% chase rate over his last seven starts, better than the 28.7% mark the league has put up over that time. That has translated into more strikeouts, as his strikeout rate has risen to 23.5%, and a reduction in quality of contact, as hitters are managing just a .337 weighted on-base avearge (wOBA) on contact compared to .532 in his first six starts. Both have led to a 3.48 ERA along with a 3.36 xERA, showing there is a potential improvement in run prevention skill.

On the flip slide, Cecconi has been an example of a pitcher who's found instant success. In three starts and two long relief appearances, he's pitched to a 2.57 ERA/4.03 FIP over 21 innings. Four of his five appearances were at least four innings. In his last start, he exhibited the necessary command of his 94-96 MPH fastball to be a capable big league starter. He started exhibiting more swagger on the mound, seen after he struck out Christian Encarnacion-Strand with a well-placed fastball.

Slade Cecconi, Painted 95mph Fastball...and K Strut. pic.twitter.com/hQKeSO6q4t
— Rob Friedman (@PitchingNinja) August 27, 2023

"I think Slade's done very well for himself" said Strom. "He has confidence in his fastball, slider's been good, competes well. Seems to be carefree when he pitches, he doesn't get too nervous, he's out there winging it."

With these two young starters stepping up, along with a successful return for Zach Davies, the D-backs may now have their most capable starting five during the season. Having a capable rotation can create a cascading effect that allows the hitters to relax and focus on having quality at-bats as well as make the bullpen's job easier.

"That's what starting pitching does" said Lovullo. "They go out there and have quality outings, it allows us to sit back and sort through your bullpen the right way."

With the D-backs currently at 69-62 and holding onto a Wild Card spot by a game and a half, they need all the quality starts they can get. As Pfaadt and Cecconi continue to get experience, it should not only help their chances of competing in 2023, but also 2024 and beyond.