DENVER -- Rockies right-hander Chad Bettis' season took another odd twist Saturday when he landed on the 10-day injured list with a left hip impingement, retroactive to Wednesday.

The Rockies added a fifth starter, Chi Chi Gonzalez, to their roster, recalling the right-hander from Triple-A Albuquerque.

“Chad has had some hip discomfort for a couple weeks, and this hip impingement has caused him to finally get to the point where he wasn’t able to manage it,” Rockies manager Bud Black said. “His competitiveness and his desire to pitch and battle finally got to the point where the hip was too bothersome for him to continue.”

Black said the severity of the injury has not been determined.

Bettis had an 8.78 ERA in three starts before the Rockies shifted him to the bullpen. There was an immediate uptick in his fastball velocity and overall stuff, and through his first 16 relief appearance, he had a 1.46 ERA and 18 strikeouts against three walks in 24 2/3 innings.

But in Bettis' last 20 games, he posted a 9.12 ERA, with seven home runs allowed in 25 2/3 innings and 15 strikeouts against 10 walks. He dealt with the hip issue for about six appearances. Black noted that fastball command and pitch quality waned when Bettis' performance dipped.

Bettis, 30, is having his mixed performance while heading into his final year of arbitration eligibility. The Rockies, facing multiple questions in their bullpen, must determine if he can be part of it going forward.

“You look at his first 20-25 innings and his last 20 or so innings, it’s been a little bit of a drastic change in performance,” Black said. “But overall, he’s adapted to the mentality of the reliever, coming to the park every day, knowing you might potentially be in there. That’s a different mindset from a starter.

“He’s handled that well. There’s a part of him that has relished that, potentially being in the game every night. Physically, being able to pitch back-to-back games, four out of seven days, he handled that very well and held his stuff for the most part.”

Injury updates

• It could be a while before the Rockies know much about the recovery of left-hander Tyler Anderson, who underwent an intricate, season-ending surgery to correct a chondral defect in his left knee after posting an 11.76 ERA in five starts. Anderson is rehabbing in Arizona, where the Rockies train, and in his hometown of Las Vegas.

The surgery was to correct damage to the cartilage that lines the ends of the bones in the knee.

“He's just gaining strength, in the knee and the quad,” Black said. “He's active. But we won't know until he starts on the real daily activity of being a professional athlete, when the intensity ramps up and you do the things you need to do to be an active Major Leaguer.

“We'll see if the surgery was successful. He can probably play catch and some toss. I think he'll be in uniform again and give it a go.”

• Black said the Rockies will check on the progress of All-Star outfielder David Dahl, who went down with a high right ankle sprain on Aug. 2, when the team is in Arizona starting Monday. Dahl is out of his walking boot and working out in Scottsdale, Ariz., but more will be known soon as far as his timeline for returning.

“He’s doing better – he’s out of the boot, he’s on the treadmill, he’s doing exercises, he’s feeling much better,” Black said. “We’ll have more of an indication about maybe a timeline. Maybe by Monday, we’ll have more information as far as a timeline or if some baseball activities are increasing.”