Arizona Diamondbacks pitchers competing for the fifth rotation spot

The Arizona Diamondbacks have an outstanding 1-4 at the top of their starting rotation. Zac Gallen, Merrill Kelly, Eduardo Rodriguez, and Brandon Pfaadt head the rotation. But the fifth spot is a little more up in the air. Currently, there isn’t a definite number five starter for the Snakes. But there are a handful of players you could see as the team’s number five starter. A good Spring Training could change the tide of things, but as we approach the pre-season, here is who could secure the number five rotation spot for the Diamondbacks right now.

Tommy Henry

Tommy Henry might have the inside track for the 5th rotation spot. The left-hander didn’t do badly in his 2023 rookie campaign, and had he continued to pitch like that over a larger sample size, the role may have been his until he proved otherwise. But he was limited to just 89 innings last year, which leaves the opportunity for someone else to swoop in and overtake Henry.

Henry had a 4.15 ERA, 4.88 FIP, and 1.36 WHIP. He had a poor 16.8% K rate along with a below-average 9.2% walk rate. His HR/9, however, was slightly better than the league average, sitting at 1.21. Henry also had some solid batted ball numbers. He was in the 73rd percentile of exit velocity (87.9 MPH), 89th percentile of hard-hit rate (32.4%), as well as the 54th percentile of barrel rate (7.6%).

Although Henry had a solid ERA and was good at limiting hard contact, there are some underlying factors that are worrying. He had a 5.29 SIERA, 5.40 xFIP, and a a 130 DRA- (95 ERA-). Sure, while Henry would be filling the role of a 5th starter, and you’re not going to expect your 5th starter to be an ace, you’d probably want something a little better than an ERA above 5.00.

As of right now, I’d say that Henry is one of the more likely candidates to secure the 5th starter job. Given that he didn’t do poorly last season, he will give him a leg up on the rest of the competition. However, I definitely would not say he’s set in stone as the 5th starter. At the very most, it’s his position to lose.

Slade Cecconi

Slade Cecconi was the D-Backs’ first-round pick in 2020. Ranked as a consensus top 15 D-Backs prospect, Cecconi made his MLB debut last season. He didn’t pitch enough to qualify for rookie status, so he’ll still be a rookie on Opening Day 2024. It would not be all that surprising if Cecconi won the final rotation spot in Spring Training.

Cecconi spent most of his year at Triple-A Reno, where he had a 6.11 ERA, 5.69 FIP, and 1.38 WHIP. Cecconi had a quality 23.3% strikeout rate along with an outstanding 7.1% walk rate. Home runs were his kryptonite, as he had a 1.80 HR/9 rate. A 17.1 HR/FB ratio, however, points to some future positive regression. Plus, it was the Pacific Coast League, so take his bottom line with a grain of salt.

In Cecconi’s brief 27 MLB innings in 2023, he only allowed 13 earned runs on four home runs and 27 total hits. He was great at limiting walks, allowing just four free passes, but he only struck out 20 batters. Of his seven outings and four starts, only one saw him give up more than three earned runs. His stuff looked decent in his brief call-up, as his fastball had nearly 13 inches of horizontal break, while his slider had 43 inches of drop. Cecconi also throws a curveball and change-up, and he controls his stuff pretty well.

Cecconi is heading into his age-25 season. If he continues to pitch like he did in his brief MLB call-up, he’ll work perfectly fine as the team’s 5th starter behind Gallen, Kelly, Rodriguez, and Pfaadt. Cecconi certainly deserves a chance to secure the final SP spot, but he has the least MLB playing time of the players we talked about thus far.

Blake Walston

Blake Walston is another former first-rounder and another one of the D-Backs’ top prospects. He isn’t as highly regarded as Cecconi, but he still ranks top 30 among MLB Pipeline, FanGraphs, and Baseball America. Walston made it to Triple-A last year, where he posted some solid numbers and was added to the 40-man roster to protect him from the 40-man roster.

Walston pitched 149.1 innings in 30 starts, working to a 4.52 ERA, 5.39 ERA, and 1.58 WHIP. Keep in mind his ERA was over a run better than the league average in the PCL. But Walston had some worrying peripherals. He walked 14% of the batters he faced. On top of that, he had a K% of 15.6%. His 0.54 HR/9 looks great on paper, but he also had a 5.3% HR/FB ratio, so there’s bound to be some regression.

I would give him a little slack, though. This was the first time he ever pitched with the automated strike zone, and some pitchers had some trouble adjusting to that last season. Walston sits in the low 90s with his four-seam fastball, but his slider and change-up have the potential to be plus offerings. His curveball also has average potential.

Walston’s stuff took a step back from 2022, but he still has the potential to be a cog in the Diamondbacks’ rotation. Walston is still a little young as he won’t turn 23 until late-June. He has a longer shot to make the team’s starting rotation.