The Diamondbacks termed Doug Davis' thyroid cancer surgery "successful" after the procedure Thursday, although few other details were released.
The procedure was performed by Dr. Bob Evani.
"Doug is awake and doing well," D-Backs team physician Dr. Michael Lee said.
"The only complaint he had was a mild sore throat, which is expected. He will likely be released tomorrow and will begin follow-up treatments at that point."
The D-Backs have a news conference planned at 5 p.m. today to discuss the operation, which has a 97 percent success rate, according to medical authorities.
Davis said he has targeted the D-Backs' series in Chicago on May 9-11 for his return.
Dr. Lee said at an earlier news conference that a general recovery window is 4 to 6 weeks.
The D-Backs were taken by Davis' composure in his last start, an 8-2 victory over Los Angeles on Tuesday in which he gave up only two runs in six innings and added two singles, one of which drove in a run, and a sacrifice bunt.
"I had goose bumps when he went out on the mound," manager Bob Melvin said.
"I had goose bumps when he came off the mound. We'll all be thinking about him."
Davis received a standing ovation when he left the game Tuesday, a tribute that grew until he stepped out of the dugout and waved his hat.
Davis' mother also has been treated for thyroid cancer.
Even after a day off the D-Backs lead the major leagues in runs and home runs with 54 and 17, respectively.
Rather than crow about it, they consider it a validation of the spring work the players and hitting coach Rick Schu did in building on a strong 2007 finish.
"The focus going in was, 'were we going to score enough runs?' " Melvin admitted. "To be able to put up the numbers we have is encouraging and can be positive for the mind-set going forward. We have to keep it going, obviously. So far, I don't think we could draw it up any better, offensively, to start the season."
Mark Reynolds leads the majors with five homers and 13 RBIs.
The D-Backs are 6-0 in the NL West after sweeping three-game series against Colorado and Los Angeles at the at the start of a 22-game stretch against division foes.