Will D-backs Abysmal Free Agent Starter Track Record Repeat?

In lieu of past failures with free agent pitching signings, questions arise after the latest injury news.

Apr 24, 2025; Phoenix, Arizona, USA; Arizona Diamondbacks pitcher Corbin Burnes (39) throws in the second inning against the Tampa Bay Rays at Chase Field. Mandatory Credit: Matt Kartozian-Imagn Images / Matt Kartozian-Imagn Images

The Arizona Diamondbacks have been big players in the free agent starting pitching market over the last five years. In total they've paid or committed $423 million dollars to four different pitchers.

Starting out for the 2020 season, Arizona signed Madison Bumgarner to a five year, $85 million dollar contract. Ahead of the 2024 season the D-backs signed another lefty, Eduardo Rodriguez, to four years, $80 Million. Then they added Jordan Montgomery just as the season got underway to a one year, $25 million with a player option that for 2025 that vested at $22.5 million.

Then the big news of the most recent offseason was the signing of free agent pitcher Corbin Burnes to a six year, $210 million contract.

To say the D-backs have not had much luck with these signings would be a gross understatement. The table below shows how much production the team has received year to date, how much they've paid out year to date, and how much more money is still owed.

Diamondbacks Free Agent Pitcher Cost and Production / Jack Sommers

On average, the amount paid on the free agent market comes out to roughly $8 million for one WAR. That means if the Diamondbacks had simply received just market value in the cost paid out through this point in time ($139 million) they should have gotten at least 17 WAR in production.

Instead they've received -2 WAR in total from these four pitchers. That's below replacement level value. Replacement level (the R in Wins Above Replacement) is the expected production a team should get from a replacement pitcher from their minor leagues. This means that these pitchers have combined to produce worse value than they could expect from the minor league system.

The Bumgarner contract has been much discussed over the years, and simply never worked out. He had simply broken down by the time the D-backs got him, and was no longer the pitcher that gave the San Francisco Giants and their fans the best memories of a generation.

In 69 games as a Diamondbacks he posted a 15-32 record and 5.23 ERA. He was released one month into the 2023 season under acrimonious circumstances.

Jordan Montgomery was thought to be a savvy signing at the time, but had a disastrous season in 2024. Pitching to a 6.23 ERA in 117 innings, he ended the year demoted to the bullpen. He just never looked like the solid pitcher he had been over the previous three or four seasons, nor the postseason hero that helped the Texas Rangers to a World Championship in 2023.

The D-backs failed to trade him during the offseason, and then he suffered an elbow injury in the spring, requiring season-ending Tommy John Surgery.

In both the Bumgarner and Montgomery cases, it was total sunk cost, with no chance of recovery. But there is still quite a ways to go with Rodriguez and Burnes' contracts, but neither has gotten off to a good start.

Rodriguez suffered a lat strain towards the end of spring training in 2024 and missed the first four months of the season. He made 10 starts and went 3-4 with a 5.03 ERA. So far in 2025 he is 1-3 with a 5.92 ERA. As poor as the results have been in his first 17 starts under this contract so far, it would not be fair to omit the fact that Rodriguez has pitched to a a lot of bad luck this season.

His expected run prevention metrics are all much lower than his ERA, including xERA from Statcast (3.42), as well as FIP and xFIP from Fangraphs 4.05 and 3.38 respectively. He's striking out 10.7 batters per nine innings while walking just 2.84. But he's been plagued by poor defensive support (4 unearned runs) and poor bullpen support (four of six bequeathed runners have scored).

That brings us to Corbin Burnes. Despite a 3.58 ERA, he has hardly looked like the dominant Ace level starter the D-backs invested in. His strikeout rate is at a career low 7.7 per nine innings pitched. That's part of a multi-year trend that has seen this number drop every year for five consecutive years.

At the same time Burnes is also walking a career high 4.68 per nine. Due to these numbers his expected ERA from Statcast is 5.34 and his FIP/xFIP are 5.09 and 4.37.

Finally, news broke over the weekend that Burnes needed to return to Arizona to get an MRI on his shoulder. He had been dealing with shoulder soreness for the previous several starts, but the team let him pitch through it.

The MRI came back clean according to Torey Lovullo, and they hope Burnes will avoid an injured list stint. But the fact is he will miss his first start since 2020 on Monday when the team faces the Mets. The team is optimistic Burnes will be able to start on Saturday against the Los Angeles Dodgers.

No matter how the team wishes to frame it, just five weeks and six starts into a six-year, $210 million contract, Burnes has looked like a shadow of his former self and is now dealing with a shoulder injury.

SUMMARY

The history of age 30 something starters in free agency is littered with athletes that have dealt with the compounding effects of injury and declining performance. For large market teams it might still make sense to make these kinds of investments, even if a relatively low percentage provide the bang for the buck in terms of WAR and Dollars calculations.

After all, we've seen how one deep playoff run and a World Series appearance in 2023 created a windfall for the Diamondbacks, allowing owner Ken Kendrick to plow money back into team. The D-backs have broken their franchise spending on payroll records two years running.

Most, if not all of these contracts were looked upon favorably in the industry at the time of signing, including by myself. But it might be time for both ownership and the baseball operations group to evaluate if these types of contracts are advisable going forward for a team that is still going to be a mid tier payroll club in the future.

With the current way starting pitchers' workloads are managed, just 5.2 IP per start compared to 5.8 10 years ago, there are already diminishing returns. Add to that the max effort style of pitching used to create velocity, spin and movement, leading to ever increasing pitcher injuries, and the risk/reward calculation has gotten too one-sided.

For more on this topic, be sure to tune in to the Snakes Territory Podcast where Jesse Friedman discussed this issue at some length.