PHOENIX -- D-backs manager Kirk Gibson tweaked his rotation for the weekend series against the Giants, pushing Josh Collmenter from Friday to Sunday and moving up Joe Saunders and Ian Kennedy.

The move accomplishes three objectives.

First, it gives Collmenter some extra rest. The right-hander has thrown 153 1/3 innings so far this year, the most in his professional career.

Second, because Thursday was an off-day, Kennedy will be pitching on regular rest rather than getting an extra day.

And finally, in case the D-backs were to drop their final six games and the Giants won their final six, the two teams would meet in a one-game playoff next Thursday and Kennedy would be set to go on regular rest for that contest.

"Not planning on it," Gibson said of the one-game playoff scenario. "We just have to be prepared, not for the worst, just be prepared."

D-backs sell out Saturday's game

PHOENIX -- The D-backs' game against the Giants on Saturday is sold out.

"We are ecstatic about the tremendous fan support and playoff-like atmosphere for such a crucial series," D-backs team president/CEO Derrick Hall said. "Every game is important and has significant impact on potential postseason play. We look forward to our fans cheering us on to a division title and hopefully home-field advantage at Chase Field."

Tickets are still available for Sunday's game with the Giants as well as Monday, Tuesday and Wednesday against the Dodgers.

The D-backs have sold out two other games this year, Opening Day against the Rockies and Sept. 10 against the Padres.

D-backs add lefty depth with Zagurski

PHOENIX -- The D-backs acquired left-handed reliever Mike Zagurski from the Phillies on Friday for a player to be named or cash.

The 28-year-old was 4-0 with 11 saves and a 2.65 ERA in 46 games for Triple-A Lehigh Valley. While he will join the D-backs this weekend, the move was more designed to give the team some left-handed options next season.

"It's an area where we don't have depth," D-backs GM Kevin Towers said.

The D-backs currently have three lefties in the bullpen -- Joe Paterson, Alberto Castillo and Zach Duke -- but after trading Jordan Norberto to the A's in July, they don't have many lefties at the top end of the farm system.

Zagurski is out of Minor League options, so if he does not make the team next spring, he will have to be put on waivers before he can be sent down to the Minors.

Towers said the team was impressed by Zagurski's velocity, which can touch 94 mph, and the fact that he strikes out a lot of hitters. With Lehigh Valley, he fanned 63 in 54 1/3 innings. He also pitched 3 1/3 innings for the Phillies this year.

On the downside, command is sometimes an issue for Zagurski, who walked 27 for Lehigh Valley.

To make room for Zagurski on the 40-man roster, the D-backs designated right-hander Esmerling Vasquez for assignment.

"I didn't see him being on our club next year," Towers said of Vasquez, who spent most of this season with Triple-A Reno.