The Arizona Diamondbacks have been putting on a juggling act with their pitching staff the last 10 days. On September 2, and then again on September 7, they were forced to utilize bullpen games rather than turn the ball back over to ineffective rookie starters Mitch Bratt and Kohl Drake. Then, on September 8, Corbin Burnes made his long-awaited return from Tommy John surgery rehab. He threw three scoreless innings, but due to pitch count limitations he was lifted after just 57 pitches. Lovullo said that Burnes would be able to throw 65-70 pitches his next outing. On September 9, Zac Gallen and Michael Soroka were activated from the IL. Gallen started, throwing 3.1 innings and 68 pitches, allowing two runs. After Derek Law cleaned up the final two outs of the fourth, Soroka came out for the fifth inning, "piggybacking" Gallen. Soroka went four innings, 58 pitches, and then continued to throw more pitches in the bullpen after the game. He gave up a three-run homer to Bobby Witt Jr. in the fifth, but then followed that by retiring 11 of the next 12 batters faced. Diamondbacks Face Difficult Decisions Next Week vs MarlinsAug 22, 2026; Phoenix, Arizona, USA; Arizona Diamondbacks manager Torey Lovullo (17) looks out to the field against the Cincinnati Reds in the second inning at Chase Field. Mandatory Credit: Anna Carrington-Imagn Images | IMAGN IMAGES via Reuters ConnectThe D-backs play the Marlins for three games starting Monday, September 14. Burnes lines up for the first game, but would only be able to throw four or five innings. Both Gallen and Soroka line up to pitch on the 15th, but both are stretched out enough to throw 75-80 pitches. That creates a dilemma. The D-backs don't want to go to a six-man rotation, but exactly who will start and and who will piggyback going forward isn't clear. "We got to make that decision. Who's gonna help us get the most outs, and pitch deep into the game? And it's a hard decision," manager Torey Lovullo said. Discussing that decision process, Lovullo indicated there will be many voices in the room with different opinions and processes to sort through. "We're gonna we're gonna thoroughly look at everything that we possibly can. There's a group that will be data-based, I'm sure, that are gonna support one side. There's gonna be others that just want to win baseball games and give their own personal gut feel," he said.The Data Favors Michael SorokaAug 22, 2026; Phoenix, Arizona, USA; Arizona Diamondbacks pitcher Michael Soroka (34) throws against the Cincinnati Reds in the third inning at Chase Field. Mandatory Credit: Anna Carrington-Imagn Images | IMAGN IMAGES via Reuters ConnectFrom the data side of the argument, it seems there should not be much of a debate. Soroka has been by far the more effective arm overall this season, and despite giving up the three-run homer to Witt, his stuff looked and graded out much better than Gallen's during his outing. Gallen has a 6.22 ERA in 101 innings this season. His expected ERA of 6.68 and FIP of 5.41 are underlying peripheral-based metrics that indicate he's truly deserved those poor results. His four-seam fastball, which he barely used, was just 91.2 MPH, down 2.2 MPH from his season-average 93.4. Gallen threw his slider more than any other pitch, 25 times, but generated just one swing-and-miss. The slider was hit hard several times, including a long home run on one right over the middle of the plate. Soroka has a 3.53 ERA on the year, to go with a 4.31 xERA and 3.04 FIP. His run prevention results, as well as peripherals, have been far superior to Gallen's all season, with the exception of the September 9 outing. Soroka's velocity was up across the board on Wednesday. His sinker clocked in at 94.2, compared to his 93.6 season average coming in. Even his trademark slurve was a little harder, with higher spin rates and more movement. Soroka's command was off in his first inning of work, walking a batter ahead of Witt before grooving a sinker middle-middle to the star shortstop. He was dominant following that, however. Ryne Nelson's Return Next Week Requires Roster MoveJun 15, 2026; Phoenix, Arizona, USA; Arizona Diamondbacks pitcher Ryne Nelson against the Los Angeles Angels at Chase Field. Mandatory Credit: Mark J. Rebilas-Imagn Images | IMAGN IMAGES via Reuters ConnectRyne Nelson is rehabbing with Triple-A Reno, and will pitch one more outing on September 12 before returning to the D-backs roster next week. When he is activated, somebody will have to be DFA'd to make room.The options on that front could possibly include Gallen, or one of two relievers Law or Dennis Santana. Both Law and Santana have been very effective in small sample sizes since joining the big league club. Santana has thrown seven innings, allowing one run and striking out nine with the D-backs. Law has also given up just one run in 7.1 innings, walking one and striking out three. Add us as a preferred source on GoogleFollow