D-backs counting on Zac Gallen, Merrill Kelly to start 8 of 16 games in postseason push

The Arizona Diamondbacks have mapped out their starting rotation to create as many outings for top starters Zac Gallen and Merrill Kelly as possible.

Gallen — coming off his first nine-inning complete-game shutout on Friday — will get the ball Wednesday against the New York Mets to kick off the final 16 games of the regular season. With Arizona clinging onto the final National League Wild Card spot entering play, Gallen and Kelly are in line to start eight of its games down the stretch.

“I think the starting pitching has been solid, I think we get some opportunities to see some improvements in that and then hopefully get some better outings over these final 16,” assistant general manager Mike Fitzgerald told Arizona Sports’ Wolf & Luke on Wednesday. “We’re gonna lean on our two big guys. … They’re gonna get eight of these 16 starts to try to put us in the best spot to finish this thing off strongly.”

They are set to start Wednesday and Thursday vs. the Mets. That leaves both of them available for next week’s two-game home series against the San Francisco Giants, a club that currently chases Arizona for the third wild card spot.

Gallen would get full rest to pitch on Sept. 24 at the Chicago White Sox and Kelly the following day at the New York Yankees. That takes them to the final series of the regular season against the Houston Astros, in which the D-backs have options to use them in the opening two games, split them up or the final two contests.

Manager Torey Lovullo has said several times this year that he envisions their playoff hopes coming down to Game 162. Pitching coach Brent Strom presented a scenario of Arizona’s playoff hopes hanging in the balance with Astros slugger Yordan Alvarez hitting with two runners on and two outs late in a one-run game on the final day.

If the season becomes a win-and-you’re-in, The D-backs plan to have one of their best horses ready. This is a process that went into motion last month when the D-backs mixed around their rotation entering the final week of August to get Gallen and Kelly together.

“If you project it and build it out for the rest of the year, you’ll tell yourself the story that’s pretty close to what we were thinking,” Lovullo said at the time. “So we want to maximize Zac and Merrill’s ability to hit the right teams and pitch as often as possible in the most critical moments.”

Zac Gallen’s 2Ks in the 3rd.

5Ks thru 3. pic.twitter.com/nOuud09aZ3

— Rob Friedman (@PitchingNinja) September 8, 2023

The Diamondbacks are 32-24 when their top two starters pitch and 44-46 with everyone else. Only six pitchers in the National League have thrown 150 innings with 60% quality starts. Gallen and Kelly are two of them, according to Stathead.

Gallen and Kelly have accounted for 7.7 wins above replacement (FanGraphs), while every other start made by a D-backs pitcher — openers and all — have combined for 2.1. Tommy Henry accounted for 0.7 fWAR as a starter, and he is out with an elbow injury.

The current version of the rotation includes Gallen, Kelly, rookie Brandon Pfaadt, Zach Davies and rookie Ryne Nelson. The latter three have allowed 22 combined earned runs over their last two appearances each (26.2 innings) for a 7.43 ERA. The D-backs used an opener ahead of Pfaadt for his most recent outing.

The Diamondbacks will need to survive with their other arms in a three-game series against the Chicago Cubs at Chase Field this weekend. They have not announced their three starters.

What has helped the staff lately has been the effectiveness of the bullpen, which owns an MLB best 1.57 ERA over its last eight games.

“One of the good trends that jumps out is our bullpen play over the last 20 games or so,” Fitzgerald said. “I feel like those guys have done a really nice job of helping us bank W’s and convert late-game leads into wins.”

Arizona led the Cincinnati Reds by a game entering play on Wednesday. The Giants and Miami Marlins were 1.5 games back, and the Cubs two games ahead. The D-backs hold the tie-breaker against none of the three teams chasing them, but they can claim the season series over the Giants with two wins next week.

If the D-backs can build a lead, that would give them more flexibility on how to prepare for the playoffs with the top two starters in mind.

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