PHOENIX -- The Arizona Diamondbacks have designated Trevor Cahill for assignment, a move that could send the struggling right-hander to the minors.
Cahill, acquired in a trade with Oakland in 2012, had lost his job in the rotation after a series of bad outings then struggled in a bullpen role.
The team also placed third baseman Eric Chavez on the 15-day disabled list with a sore right knee.
The Diamondbacks activated right-handed reliever J.J. Putz from the disabled list and recalled right-handed reliever Will Harris from Triple-A Reno.
The Diamondbacks have 10 days to either trade Cahill, release him, outright him or option him to the minors.
If they outright him, the pitcher would go on waivers and could be claimed by other teams. That and a trade are unlikely because Cahill is due to earn about $17 million in a contract that runs through next year, and Cahill seemed to be open to the idea of going to the minors, probably to Reno.
"Our hope is to retain him," Diamondbacks general manager Kevin Towers said. "We still think there's value there."
Cahill , 1-6 with a 5.66 ERA, had his best years with Oakland. In 2010, he was 18-8 for the A's with a 2.97 ERA.
"After everything that's happened, I still believe I can come back and be a starter and help this team win," he said before Monday night's game against Houston. "I mean, they've been nothing but supportive and I can't ask f or anything more."
Manager Kirk Gibson noted that Cahill is only 26.
"This game's tough. There's a lot of people that struggle," Gibson said, "and they have to find a way to get back to what they can be. Again, it's a tough game, but I still believe in Trevor. I have confidence in him. He's young. He's got that going for him."
Cahill was particularly aggravating to the Diamondbacks because at times he had spectacular stuff, but that didn't translate into success in games.
"There are times when I come out of the pen and feel real good and starts when I feel really good, it's just the starts that I don't feel sharp," he said. "I've just got to figure out a way to kind of get through it and still help the team win."
Towers said that Cahill is not suited for a bullpen role.
"We think his best role is a starter," Towers said. "That's what we traded for is a starter. ... It's tough to get a guy lengthened up to become a starter when he's pitching once every eight or nine days in relief."
Asked if he regretted the trade, Towers said that he doesn't look back once a deal is made.
"I still believe in the kid," he said.
Cahill voiced confidence in the Diamondbacks' front office.
"I'm sure they'll do right by me," he said. "They haven't given me any indication they wouldn't. I'm just going to do whatever is best for the team. I want to stay here but I want to get better and be the guy that I think I can be."