Jarrod Parker talks to catcher Kurt Suzuki during a Spring Training game March 19. (Marcio Jose Sanchez/AP)

PHOENIX -- Following a seven-walk outing against his former D-backs club Monday, A's top pitching prospect Jarrod Parker talked about the need to "move on." He'll have to do that in the Minors, at least for now.

Parker was optioned to Triple-A just an hour later, a move that reflected the club's desire for him to continue work on his command but one that does not preclude him from the fifth-starter spot, considering the A's can get by on a four-man rotation until April 17.

"It doesn't mean he's not in the running for the fifth-starter spot, and he knows that," manager Bob Melvin said. "I think he was very disappointed in the fact he didn't get to go to Japan and be with his teammates, and I understand that.

"He is going to be part of this team. Not right now, but certainly in the future. We feel like he's as talented a guy as we have here. That's what made it so difficult today. I wanted him to know when he got traded over here, he's not being looked at differently now. He was the guy that was the crown jewel over there. He's in that type of esteem over here."

Parker was visibly disappointed while packing his bags and said he was told by Melvin he must "figure a few things out and be ready when my time comes." He compiled a 3.27 ERA with 13 walks and nine strikeouts in 11 innings this spring.

Earlier in the day, the 23-year-old right-hander more than doubled his spring walk total. He entered the game having issued six walks and afterward said he was maybe trying to do too much, be too fine, against familiar faces.

"Seven walks is pretty brutal," he said.

Acquired by the A's in the five-player deal that sent All-Star Trevor Cahill to Arizona in November, Parker is finding out what most Tommy John surgery patients learn following the procedure -- that command is normally the last thing to come back. Melvin agreed but said Parker's fastball command, more than his breaking stuff, should have already returned by now.

"His stuff is good when he gets it over the plate," Melvin said. "He has the stuff to get behind guys and get guys out, but you just don't want to put guys on base like he did today."

"Today didn't help," Parker said, after learning of his demotion. "I strive to be better than that, and that's what I'm going to do."

The former first-round Draft pick pitched in just one big league game for the D-backs last year, tossing 5 2/3 shutout innings as a September callup from Double-A, where he went 11-8 with a 3.79 ERA.

The A's have three open rotation spots, with lefty Tommy Milone and right-handers Tyson Ross, Graham Godfrey and Brad Peacock still in camp seeking one. Parker, meanwhile, will be doing the same from afar.

"He needs to get his rhythm a little bit better, find a consistent arm slot and throw the ball over the plate, like he has in his career," Melvin said. "This is kind of against the grain for who he is."