MESA, Ariz. -- Ryan Dempster hopes he locked up a spot in the Cubs rotation Wednesday.

"He threw the ball as well as I've ever seen him throw it," Cubs manager Lou Piniella said.

The right-hander struck out seven and gave up one hit and two walks over 5 1/3 scoreless innings in the Cubs' 5-2 loss to Oakland. His days as a reliever, Dempster says, are over.

"I'd like to believe they're behind me," he said. "I'd like to believe I can do a good job starting."

This was Dempster's fifth start, and the right-hander is trying to convince the Cubs he is ready to return to the rotation after three seasons as the closer. Jason Marquis, battling to secure one of the openings, struck out four, walked two and gave up five hits over five-plus innings on Tuesday against the Kansas City Royals. Jon Lieber, also in the mix, started Wednesday in a night game against the San Francisco Giants. The final five should be announced this weekend, at the latest.

"What else do we need to see? They're all throwing well," Piniella said. "Make a decision, go with it, live with it, and it'll be fine."

This was a much improved outing after Dempster's last start, when he gave up six runs on five hits over 1 2/3 innings.

"It's one of those things where the five days can't come fast enough," Dempster said. "When you're relieving, you get a chance sometimes the next day. I felt like [Wednesday] was the way I've been throwing all spring, and I just had a little hiccup [in his previous start]."

He's cured that problem. Dempster was more enthused about how well he felt after his outing than the stats. How does he feel about his chances to make the rotation?

"I felt good all spring and felt good today, and that's their decision to make," he said. "I'm trying to make it as easy as possible for them."

Actually, the decision will be tough for the Cubs. Piniella expects to finalize both the rotation and the closer situation before the final week of spring games. Now, if he could just get the bats going.

"Offensively, it's been hard scoring runs down here," Piniella said. "Usually in Arizona, you score a lot of runs, and this spring here there's been a scarcity of runs."

The Cubs have been playing well. They just aren't hitting.

"I've sounded the warning bell before," Piniella said. "Sooner or later, we have to start swinging the bats."