SAN FRANCISCO -- To prevent Tim Lincecum and Randy Johnson from receiving too much rest, manager Bruce Bochy shuffled the starting rotation to keep the Giants pitchers on a more regular schedule.

Lincecum, Johnson and Matt Cain will receive the starting assignments, in that order, for this weekend's series against the Arizona Diamondbacks in Phoenix. Originally, Jonathan Sanchez was to pitch Friday, followed by Lincecum and Johnson.

But this week's pair of scheduled off-days Monday and Thursday would have forced Lincecum and Johnson to get six days' rest apiece had the Giants stuck to their prescribed pitching sequence. That's two days' rest more than usual, enough to throw a starter off his routine.

With the change, Lincecum and Johnson will have five days' rest before they pitch again, a more manageable break. Cain will work on his typical four days' rest.

The odd man out is Sanchez, who pitched 6 2/3 shutout innings against Arizona last Friday. In hopes of keeping him sharp, the Giants have made him available to work in long relief over the next few days. Then they can insert him back into the rotation for one of the first two games in San Francisco's three-game series against Los Angeles (April 27-29). Lincecum, back on four days' rest, will pitch the finale of that series.

Bochy acknowledged that Sanchez is coming off an excellent outing, but pointed out that the left-hander has bullpen experience and should be able to handle the brief change. Bochy added that any rest Sanchez might get should benefit him. Sanchez needed a stint on the disabled list last August to treat a strained left shoulder.