The D-backs Stay in the Race Despite Lack of Reliable Rotation Options

During the 2023 season, a common theme when looking at the Diamondbacks' pitching staff was to break out the numbers of the top two starters, Zac Gallen and Merrill Kelly, and compare that to all the non-Gallen and Kelly starts. As you might imagine, those number were not pretty.

Gallen and Kelly made 64 starts, and went a combined 29-17 with a 3.39 ERA. In the other 88 starts that weren't bullpen games the starters went 17-31 with a 5.77 ERA. In fact over the second half of the season manager Torey Lovullo began to frequently utilize openers and bullpen games.

That strategy extended into the postseason, but ultimately caught up with the Diamondbacks in Game 4 of the World Series. Lacking a fourth starter, he was forced to deploy a bullpen game, with disastrous results as the Texas Rangers jumped out to a 10-0 lead en route to an 11-7 victory.

The D-backs were roundly criticized for this, and GM Mike Hazen beat himself up over the offseason over his inability to acquire a starter at the trade deadline. So he set about to fix that by signing Eduardo Rodriguez to a four year, $80 million dollar contract. Then on March 29th he signed Texas postseason hero Jordan Montgomery to a one year deal worth $25 million that included a vesting player option for 2025.

Surely this would give the D-backs one of the best rotations in the game. As we all know, that's not how it's played out. Rodriguez got hurt in spring training, and has not thrown a pitch. Kelly made just four starts before going on the IL April 23rd.

Neither pitcher is expected to pitch until about the All Star break in mid July. Gallen meanwhile has missed several starts with a hamstring injury and is at least 7-10 days from returning, if not longer.

Much like last year, the non Gallen and Kelly starters have failed to provide any consistency, with the exception of Brandon Pfaadt. While his ERA is higher than league average, he's gone deep into games consistently and based on FIP (Fielding Independent Pitching), has pitched better than his ERA indicates, likely running into some bad luck.

As for the rest of the starters, well as can be seen below, there is once again a gap of over two runs in the ERA number. (3.53 vs. 5.65) Note that the games where Ryne Nelson, Slade Cecconi, and Blake Walston were the "bulk" pitchers behind an opener ARE included in the numbers below. aWAR is the average of Baseball Reference and Fangraphs WAR, incorporating both systems of measurement.

D-backs starting pitcher groups | Jack Sommers

Other than the ERA and FIP, another important thing to note is the innings pitched per game. The top three in the chart average 5.75 IP per game. (155.3/27). The bottom five in the chart are averaging just 4.9 IP per game.

The team desperately needs another starter to step up and join that top group. Obviously it should have been Montgomery, but he's been getting hit hard. Unfortunately he has seen his sinker velocity drop by 1.5 MPH this year compared to last, and the pitch has just not been effective for him at all. Without his signature pitch working for him, he is a shadow of his former self, with no clear pathway back to effectiveness at the moment.

The D-backs may be forced to go with an opener once again on Sunday. Walston was just placed on the injured list with left elbow inflammation. They called up starter Humberto Castellanos to provide length and depth in the bullpen. Expect yet another move by Sunday, bringing up either Tommy Henry, or perhaps even Cristian Mena to make his major league debut.

Or Lovullo could opt for a straight bullpen game, utilizing seven or eight difference pitchers. All options must be on the table while the D-backs try to piece it all together while waiting to get healthy in the rotation. That's going to be at least another month. Four days ago we asked whether the D-backs survive all the rotation injuries. That story link is here.

Despite all this and a 30-33 record, the D-backs are right in the thick of the National League Wild Card chase. As of this writing they're just 0.5 games behind the Padres for the third Wild Card spot, and 1.0 games back of the Cubs for the second. Arizona is also tied with with three other teams in that position, including the Reds, the Giants, and the Cardinals. The Pirates are just 1 game out.

The opportunity is there for a young pitcher to seize the moment. So far, none, except for Pfaadt, have been able to do so. Now with yet another injury, they are thinner still. But the D-backs continue to hang on and hang in there. Stay tuned to Inside the Diamondbacks ON SI as we continue to chronicle this fascinating season.