"He'll do nothing for a week and do strengthening for the next two weeks," said Melvin, adding that he does not expect Webb to undergo further testing after an April 10 MRI showed fluid in the shoulder but no structural damage.

That will take Webb to May 15, and since he basically will be starting over in his throwing program, he is not expected to make another start until sometime in June. He felt soreness in his right shoulder in the season opener April 6, when he gave up six runs and six hits in four innings of a no-decision against Colorado, and has been on the disabled list since.

Webb threw a 33-pitch bullpen session Tuesday and reported no pain.

"We didn't expect this (Friday)," Melvin said. "He's a guy we are going to be careful with. We are not going to push him to see if he can throw through it. He's too important for us to try to push something like that."

Webb led the NL with 22 victories last season and has finished second, second and first in the last three NL Cy Young Award votes.

Webb had agreed to a $54 million contract extension last summer pending a physical exam, but the deal was pulled off the table when the D-backs' insurance carrier found what it believed was irregularities in Webb's right shoulder.

GIANTS 5, DIAMONDBACKS 1: RHP Tim Lincecum made his second consecutive dominating start against Arizona and C Bengie Molina drove in three runs and was a triple short of the cycle. Lincecum struck out 12 in eight innings for the victory, six days after striking out 13 in eight shutout innings in a game the D-backs won in the ninth. LHP Doug Davis drove in the D-backs' only run with a two-out single in the fifth inning to cut the Giants' lead to 2-1.