Diamondbacks starter Bronson Arroyo will have season-ending Tommy John surgery, according to MLB.com's Steve Gilbert.

Arroyo has been on the DL since the middle of June with a strained ulnar collateral ligament in his throwing arm, so the news doesn't come as a big surprise. The DL stint was the first of Arroyo's 15-year career, and now the right-hander will miss the rest of the season and possibly part of 2015 after he undergoes Tommy John surgery.

Per Gilbert, Arroyo said an MRI last month revealed his UCL had completely come off the bone, and the veteran hurler made six starts this season with the UCL tear in his right elbow.

Arroyo signed a two-year, $23.5 million contract with Arizona this past offseason. The D-backs also own a club option for 2016.

"I wanted to see if I could pitch on it without the ligament, because a few guys have done it," Arroyo told Maria Torres of MLB.com. "I fired it up the last three days, and I could throw 120 feet and I could probably go out there and pitch, but it just won't come back fast enough."

In 14 starts this season, Arroyo had compiled a 4.08 ERA with 47 strikeouts and 19 walks in 86 innings pitched. Even in the month of June, when he was reportedly throwing with the tear in his UCL, Arroyo allowed just six earned runs in three starts. In his last outing prior to landing on the DL on June 15, the righty gave up five hits and a run over five innings against the Dodgers.

Arroyo has been a model of durability throughout his career, throwing at least 199 innings in every season dating back to 2004, when he threw 178 innings for the Red Sox in his first full year as a starter in the majors. The 37-year-old was coming off two strong seasons for the Reds, in which he posted a 3.74 ERA in 2012 and a 3.79 ERA in 2013. Last season Arroyo struck out 124 batters while walking just 34 in 202 innings pitched.

Despite his age and the tough rehab process ahead, Arroyo did indicate to the media that he wants to return and pitch a couple more seasons.

Arroyo's season-ending injury continues a tough season for Arizona. The D-Backs' staff has posted the fifth-worst ERA in baseball through Sunday at 4.35 and their starters are fourth-worst at 4.71, as the likes of Brandon McCarthy, Trevor Cahill and Mike Bolsinger have struggled in 2014. The Diamondbacks designated Cahill for assignment in June and traded McCarthy to the Yankees on Sunday.

After his impressive rookie campaign last year, the club also lost left-hander Patrick Corbin to Tommy John surgery in March.

Little else has gone right for the Diamondbacks this season, with the team currently sitting in last place in the NL West with a 37-53 record. After acquiring Mark Trumbo, the slugger has missed time due to injury as well. Considering how poorly their year has gone, the Diamondbacks are much more in need of a healthy Arroyo in 2015 than in 2014.