Mike Hazen Making Big Bets on D-backs Starting Pitching to Rebound

The Arizona Diamondbacks' starting pitching had a rough season in 2024. They finished the year with the 27th ranked starters ERA in MLB (4.79). Some of that was due to injury, as Merrill Kelly and Eduardo Rodriguez both suffered shoulder injuries, limiting them to 13 and 10 starts respectively.

The minor league pitchers who were called up to fill in those starts provided mixed results. Ryne Nelson had a breakout second half, and Yilber Diaz showed promise in four starts. Tommy Henry and Slade Cecconi struggled however and bounced back and forth between the majors and Reno.

Of course beyond that, last minute free agent signing Jordan Montgomery had a disastrous season, posting a 6.23 ERA and losing his rotation spot by September.

General Manager Mike Hazen has held steadfast in his belief in his starting pitching depth however, so much so that when speaking on the MLB Network on Monday, he used the phrase "excess starting pitching."

Indeed, as things shake out right now the Diamondbacks will enter camp with six starting pitchers who could all be in the opening day rotation, including Zac Gallen, Brandon Pfaadt, Kelly, Rodriguez, Nelson, and Montgomery.

Hazen has also repeatedly mentioned that teams are inquiring about his starting pitchers, and indicated a willingness to deal from that perceived depth. They have been shopping Montgomery, but so far to no avail.

Catching up with Hazen on Monday night, I asked him if that excess starting pitching comment indicated a strong belief in prospects such as Diaz, or perhaps Yu-min Lin to step into the rotation. But he immediately pivoted to last year's minor league pitchers when providing his answer.

Surprisingly perhaps, the first names he mentioned were Cecconi and Henry, followed by Drey Jameson, who missed all of 2024 coming off Tommy John Surgery.

Cecconi was demoted to Reno, converted to relief work, came back to the majors as a reliever, but struggled, and was demoted again. His MLB season ended with a 6.66 ERA. Henry was demoted to Reno at the end of April, came back for a few games in June, and then spent the rest of the season in Reno as well. He finished with a 7.04 ERA

The faith in Henry is based upon the success he had in 2023 before suffering an elbow injury.

"I still think Tommy Henry's 12 months removed from being a stabilizing force in our rotation the year prior," Hazen said. "I don't know where things went sideways on us this year, but I expect him to be back. There's no reason why he shouldn't fill that [depth] role. He's too talented to not fill that spot in a lot of ways."

Never a hard thrower to begin with, Henry has lost velocity each year since his rookie year. In 2022 his fastball clocked in at 91.5. That dropped to 90.7 in 2023, and 90.2 in 2024.

When asked if he meant Jameson was going back to full time starting pitching, Hazen quickly clarified.

"No, but it's not off the table. I mean, Jameson is coming off of the injury, so that one's TBD. I don't have a firm idea what we're doing there. It may just be as a reliever when we get down to it, depending on how many innings we think he's going to have and where he's going to get to, come off the injury."

Torey Lovullo later spoke about stretching Jameson out to start in spring training. "He'll be stretched out initially, but how far he goes and how many innings he throws next year is yet to be determined."

Hazen still has a lot of confidence in Cecconi as well. "I mean, Slade came up last year and started for us and was ripping off five inning starts at a pretty good clip early on. I don't know where it's going to land for him, but I don't see any reason why he couldn't harness three to four pitches and start. But we'll see. I mean, wherever he maximizes, he will."

Lovullo indicated the approach with Cecconi will be similar to that as Jameson.

"We're doing something similar with Slade. I feel like as you stretch guys out and give them the
ability to repeat that delivery, you are going to find out where you are standing and what kind of stuff you have and make improvements a little bit more rapidly."

So clearly Hazen has not given up on his first wave of starting pitching prospects to make a more positive impact at the major league level.

"That's a number of good arms, no matter how you slice it, who have AAA to Major League experience that are starting to either carve their way through it or have 50 to 75 innings in the big leagues that we can feel pretty good about pitching for us at the Major League level."

Counting on this group of pitchers to fall in behind the top five or six listed starters may seem to be a gamble, but it's one that Hazen is ready to take.

"It's a deep group. I'm hoping the upside matches the depth part of it and they solidify, not just filling the spot, but actually take hold of it if one comes open. And we're going to have to make bets on in certain places."

If those pitchers fail, then the next wave of Blake Walston, Yilber Diaz, Cristian Mena, and Yu-min Lin will start to get their chances.

One thing that should be pointed out is that the D-backs clearly felt that they needed to make a coaching staff change to facilitate the growth of their staff. They fired Brent Strom, replacing him with Brian Kaplan, and have hired all new assistant coaches as well.

It's difficult to measure exactly how much impact the coaches have on actual results. This writer's default position is to not give them too much credit, or too much blame either. That doesn't mean they can't influence things. Of course good teachers and coaches are a plus. But individual relationships have a big impact too. Some players are more receptive than others when it comes to individual coaches.

Another important point is that last season's starting pitchers suffered a good deal of bad luck. While the aforementioned team ERA of 4.79 ranked 27th, various run estimators such as FIP (Fielding Independent Pitching) and xFIP were far better at 4.01 and 4.05 respectively.

That whopping 0.78 difference between the expected ERA based on peripherals was far and away the largest of any team in MLB. The next closest "unlucky" starting staff was the Washington Nationals who had an ERA 0.46 higher than their FIP. This could indicate that some positive regression to the mean could occur for the Arizona staff in 2025, regardless of who the coaches are.

It should be noted that these estimators are more predictive of future ERA than ERA itself.

The table below takes the average of three ERA estimators (FIP, xFIP and also xERA from Statcast), and shows them alongside the actual ERA, as well as the difference. A negative number means the pitcher had an ERA lower than the peripherals would suggest, whereas a positive number indicates the opposite.

In the cases where the difference is a run or more, that is extreme, and at least some measure of luck (bad or good) is involved.

D-backs Starting Pitchers ERA vs. ERA Estimators | Jack Sommers