After a 15-month absence, the Arizona Diamondbacks are set to get ace Corbin Burnes back. Burnes, who went down to Tommy John surgery last summer, is the club’s scheduled starter on September 8 against the Royals. And he jumps into the fold to help a Diamondbacks club right in the midst of a playoff push.

The numbers

In terms of quantifiable results in actual Minor League games, there’s not a lot to talk about with respect to Corbin Burnes.

The former NL Cy Young Award winner made just one official start (we’ll get to that in a second) down in the Minors before his pending activation with Triple-A Reno. That came on August 29, an outing in which he went two innings over 17 pitches. Burnes didn’t allow runs or hits in that start against the Giants’ Triple-A team.

He made tidy work in that contest, mostly using his signature cutter. Burnes also used a handful of curveballs, plus one changeup and sinker each. Aside from that, Burnes picked up three called strikes (no whiffs) and induced mostly weak contact. The lone hard-hit ball came via a 107 MPH groundball off the bat of Parks Harber.

However, much of Burnes’ rehab work was done off a Minor League mound, outside a real in-game setting. Most recently, Burnes tossed 53 pitches in a rehab game down in Arizona against Minor Leaguers last week.

During the final month of the season, one sticking point for rehabbing pitchers is how much one can be stretched out with little time left on the league calendar. At least in Burnes’ case, the D-Backs were able to do that by and large, to the point where he should be able to give the club more than just two innings.

The velocity

Early on in the 2025 season, Burnes’ velocity was down a tick. We saw fewer 95, 96, 97, and 98 MPH fastballs from Burnes, and more 92 and 93 MPH stuff. His velocity jumped up during the spring, before he ultimately went down to UCL reconstruction surgery.

During his brief rehab assignment, Burnes’ velocity stayed at 92-93 MPH, and he held it consistently with the cutter.

His stuff is still good enough to get batters out with that velocity. And one would expect a natural tick up over time. But while Burnes gets back to speed at the big-league level, he’ll be called upon to pitch in some big innings, as the D-Backs are firmly in the playoff race.

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