JULY 16: The Diamondbacks announced that Arroyo underwent successful Tommy John surgery yesterday (Twitter link).

JULY 7: Diamondbacks right-hander Bronson Arroyo told reporters today, including MLB.com’s Steve Gilbert (Twitter links), that he will have to undergo Tommy John surgery. Arroyo adds that he actually made six starts this season with a torn ulnar collateral ligament.

It’s tough to call this news anything other than poor luck for the Diamondbacks, as Arroyo has been among the game’s most durable pitchers throughout his entire career. The 37-year-old posted nine consecutive seasons of 199 innings or more from 2005-13 and was tied with Dan Haren for most games started in that same stretch (297). He has been on the disabled list since mid-June due to a UCL injury.

Arroyo signed a two-year, $23.5MM deal with Snakes this offseason due largely to that durability. The D’Backs won’t receive a great return on that investment, as Arroyo has posted a 4.08 ERA in 86 innings and likely won’t pitch again until next summer, even in a best case scenario.

Arizona has been hit hard by injuries this season, with top starter Patrick Corbin and setup man David Hernandez each going down with Tommy John surgery prior to the season. Mark Trumbo has also missed significant time on the disabled list due to a stress fracture in his foot.