Tracy started at first base in place of Conor Jackson on Monday and at third base in place of Mark Reynolds on Tuesday. He was used as a pinch hitter Wednesday.

"I don't have a formula. I don't know how it will play out. We do have regulars we run out there, which he will go in there and spell," Melvin said. "When he is not in the starting lineup, he will be a bat off the bench. The one thing we have missed a little bit is a power guy off the bench, and he gives us that."

Tracy was bothered much of the second half of 2007 with his right knee injury, when he hit .264 with seven homers in 76 games. He had breakout season in 2005, hitting .308 with a career-high 27 homers and 72 RBIs. He hit .281 with 20 homers in 2006, when he also had career highs in doubles (41) and RBIs (80).

"I think I can do what I've done before," said Tracy, who finished a rehab assignment on a hot streak with 12 hits in his final 26 at-bats for Class AAA Tucson. "I was driving the ball up the middle, which is where it starts for me. The power will come later."

Of his knee, Tracy said, "I think I'll always feel it a little bit. But I'm not saying it's going to limit me."

GIANTS 11, DIAMONDBACKS 3: The D-backs lost for the eighth time in their last 11 games, falling Wednesday in Doug Davis' return to Chase Field. In his first home start since he had surgery to remove a cancerous thyroid gland on April 10, Davis gave up six runs on nine hits in five innings. The D-backs lost their first series to an NL West opponent this season by dropping the first two games of the three-game series. They won eight of their first nine division series and split the other.