PHOENIX — Left-hander Doug Davis was placed on the 15-day disabled list today by the Arizona Diamondbacks, who recalled right-handed reliever Jailen Peguero from Triple-A Tucson.

Davis, the winner in last night's 10-5 victory over the Los Angeles Dodgers, was to undergo surgery for thyroid cancer tomorrow.

The Diamondbacks are expected to make another move on Monday, when Randy Johnson makes his first big league start since back surgery — against San Francisco.

Johnson struck out seven in six innings for Tucson against Salt Lake City on Tuesday night.

"I would think everything's a go, but I haven't talked to him yet," Arizona manager Bob Melvin said before today's game against the Dodgers.

Melvin said Johnson's fastball reached 92 mph in yesterday's outing.