Injuries and ineffectiveness have hurried up the return of Austin Gomber as a starting pitcher for the Colorado Rockies.

He's scheduled to take the mound on Saturday night against the visiting Arizona Diamondbacks in the middle game of their three-game series.

Gomber (3-7, 6.55 ERA) was relegated to the bullpen after his poor finish to May carried into June. He wasn't effective in his stint as a reliever either, allowing four runs and five hits, including two home runs, in 4 1/3 innings.

Gomber is getting another opportunity to step back into the starting rotation, however. That comes after right-hander Ryan Feltner was optioned to Triple-A Albuquerque on Monday after going 0-2 in four starts in June with an 8.64 ERA.

The need for a dependable starter in Colorado increased even more when Antonio Senzatela departed the series opener on Friday after two innings because of shoulder tightness.

The Rockies went on to lose 9-3.

Gomber is thankful to be getting another chance as a starter after his struggles in recent outings.

"Over the past three weeks or past month, I haven't been pitching up to my capability," Gomber said. "It's frustrating for myself and for the team. I felt like the starting rotation was going to be a strength for our team and I was a part of that."

The Rockies are hoping Gomber can find the touch he displayed at Coors Field last season, when he was 5-1 with a 2.09 ERA in nine starts.

Gomber is 1-0 in three career appearances against the Diamondbacks, including two starts, with a 3.86 ERA.

Arizona starter Dallas Keuchel is looking to build on his team debut with the Diamondbacks last weekend. The former American League Cy Young winner is scheduled to make his second start since he was acquired by Arizona last month.

Keuchel (2-5, 7.93) was designated for assignment by the Chicago White Sox on May 28 after giving up six runs in back-to-back starts, skyrocketing his ERA to 7.88.

The Diamondbacks signed him to a minor-league deal on June 6, and he was recalled from Triple-A Reno on Sunday. He started that day against the visiting Detroit Tigers, allowing four runs and six hits in 4 1/3 innings of the 11-7 victory. He struck out seven and walked three.

"The last 15-20 starts have been a whirlwind, kind of a rollercoaster ride for me," Keuchel said. "It's just one main key and that is keeping myself in a stable position to create late movement to the plate, and a linear line to the catcher."

The need for another dependable starter in Arizona increased when right-hander Zach Davies went on the 15-day injured list on Tuesday with right shoulder inflammation.

Arizona manager Torey Lovullo would be happy if Keuchel could duplicate his last start.

"I'm very pleased with what I saw, the preparation, the ability to command the baseball and throw it where he wants to," Lovullo said. "He went out there and started executing after the first couple of innings, so I thought it was a very good outing."

Keuchel has made just one start against the Rockies in his career and is 1-0 with a 4.05 ERA.