Skidding D-backs to Face Paul Skenes, Improved Pirates at Chase Field

The Diamondbacks will have their hands full with one of the best pitchers in MLB

Apr 24, 2026; Milwaukee, Wisconsin, USA; Pittsburgh Pirates starting pitcher Paul Skenes (30) throws a pitch in the first inning against the Milwaukee Brewers at American Family Field. Mandatory Credit: Benny Sieu-Imagn Images | Benny Sieu-Imagn Images

The Arizona Diamondbacks are returning home after a grinding 2-6 road trip to Mexico, Milwaukee, and Chicago that dropped their season record to 16-17. They have a -31 run differential, and the rotation's 5.42 ERA is the highest in MLB.

The Pittsburgh Pirates are a much-improved team. They come in with a 19-16 record and a +31 run differential. They finally have an offense that can support their excellent young pitching staff, posting a team 104 OPS+, which is above league average 100.

When most pundits looked at the schedule before the season started, they probably thought this would be a softer spot in the schedule for D-backs. But now they'll face the sharp end of the stick in the Pirates rotation, at least in games two and three of the series.

D-backs-Pirates Starting Pitching Matchups

Tuesday, May 5, 6:40 p.m. MST

Bubba Chandler and Eduardo Rodriguez pitching stats | Jack Sommers

23-year old right-hander Bubba Chandler had a successful MLB debut in 2025, going 4-1 with a 4.02 ERA after a late season call-up. That carried over through his first four starts, 20 innings this year when he posted a 3.15 ERA.

Chandler has hit a bit of a speed bump, however, allowing nine earned runs in nine innings in his previous two outings versus the Rangers and Cardinals. That's bumped his ERA up to near five, and his peripherals indicate that's about where he should be.

This issue is a blend of walks and homers, as he's issued 20 free passes and given up five homers in 29 innings. He throws a 99 MPH four-seamer 55% of the time to go with a changeup, slider, and sweeper.

Eduardo Rodriguez's hot start to the season stalled out over his last three outings. The reason is walks, as he's doled out 11 of them in 14.2 innings. His ERA is still very good at 3.03, but more regression looms if he cant get the walks under control.

The D-backs have won each of those last three games, however, and this is probably their best chance to get the series off to a good start.

Wednesday, May 6, 6:40 p.m. MST

Paul Skenes and Michael Soroka pitching stats | Jack Sommers

Paul Skenes got rocked on opening day, not making it out of the first inning, allowing five runs against the New York Mets. He then proceeded to rip off five starts in which he gave up just three runs on 10 hits in 28 innings. But the St. Louis Cardinals got him again on April 30, tagging him for five runs, four earned in five innings.

This will be Skenes fourth start against the D-backs, and second time pitching at Chase Field. In his previous three outings versus Arizona he's given up just two runs in 18 innings pitched (1.00 ERA) and allowed a .185 batting average against.

Michael Soroka had been the D-backs' most effective starter prior to his last outing, coming in with a 2.60 ERA. That shiny ERA ceased to exist after just one disastrous start in which he gave up eight runs in three innings to the Brewers on April 30.

Soroka still sports a stellar 36/9 strikeout-to-walk ratio, and has allowed just three homers. So metrics like FIP and xFIP look much better than his 4.70 ERA. Statcast, on the other hand, sees a lot of hard contact and luck on balls in play, so that metric indicates an ERA around five is warranted.

Thursday, May 7 12:40 p.m. MST

Mitch Keller and Zac Gallen pitching stats | Jack Sommers

Mitch Keller has been a solid workhorse for the Pirates over the years, averaging 31 starts a year over the last four years. He posted a 4.15 ERA, 103 ERA+ during that stretch. This year through seven starts he's been more than just an innings eater, allowing two runs or less in five of his seven starts.

Keller personally has a 3-1 record and a 2.85 ERA, but the Pirates lost two of his three no-decisions. Keller has five career starts against Arizona, going 1-0 with a 2.15 ERA in 29 innings. He did not face Arizona in 2025.

Zac Gallen was hammered by the Cubs for six runs on seven hits and three walks in 3.2 innings on May 1. That drove his ERA up to 4.45 on the season. He was coming off a truncated outing in Mexico however, in which he had to leave the game due to a bad bruise on the shoulder after being hit by a comebacker.

Gallen is attempting to re-establish his market value in 2026, but so far there are concerning signs due to lack of swing-and-miss and strikeouts. Through 2024 he had a 26.2% strikeout rate, well above the league average 22%.

But that number dipped to 21.5% last year, and is now at an untenably low 14.2%. Likewise, his 16.5% whiff rate is in just the fifth percentile, meanwhile 95% of the pitchers in MLB are getting more swing-and-miss.

Diamondbacks vs Pirates Bullpens

Apr 29, 2026; Milwaukee, Wisconsin, USA; Arizona Diamondbacks pitcher Paul Sewald (38) delivers a pitch against the Milwaukee Brewers in the ninth inning at American Family Field. Mandatory Credit: Michael McLoone-Imagn Images | Michael McLoone-Imagn Images

The Pirates have a 3.70 team bullpen ERA, compared to the Diamondbacks' 4.83. Dennis Santana, (3.07 ERA) and Gregory Soto (1.72) are the co-closers for Pittsburgh.

D-backs closer Paul Sewald had to pitch in an 8-2 ballgame in the eighth inning on Sunday, as it's been quite a while since he had a save chance.

Having not pitched more than once in the previous week, Sewald just needed to get some work in. The veteran is 7-for-7 in saves, but has an 0-3 record due to struggles in tie games. His ERA is 3.86 over 11.2 innings.