SEATTLE -- There's no rest for the weary, it turns out.

Mariners manager Don Wakamatsu had planned on giving left-hander Jason Vargas two extra days of rest before his next start, but a sore shoulder has forced Erik Bedard to the disabled list, and Vargas will instead make his eighth start of the season on Saturday, one day earlier than expected.

Vargas said he doesn't mind foregoing that extra day.

"It's perfectly fine with me," Vargas said before Friday's game. "They did give me an extra day, so I don't really know how much more I need than that."

Vargas struggled in his last outing, a 7-1 loss to Colorado that was played amid thunderstorms and tornado warnings. He was throwing to an unfamiliar catcher, Guillermo Quiroz, and Vargas also said he thought he went away from his game plan a little bit. He said after the game that he should have used his changeup more, as a fifth-inning meltdown ended up breaking the game open.

"I want to try to stay to my strengths," Vargas said. "We were working with a catcher I hadn't worked with very much. He was new to my style a little bit, too, and at the same time, it was a different lineup and a team we hadn't seen before. You've just really have to remember what your strengths are, and not just get into a pattern and keep throwing the same thing when you're not getting ahead with it."

That loss was the roughest outing of what has turned into a mini-skid for the 26-year-old, who allowed just five runs in his first five starts this season. But Vargas has lost his last two outings, yielding a total of 19 hits and 10 earned runs in those two efforts.

Those struggles were the main reason for the intended extra days off, and a little rest here and there certainly wouldn't hurt considering Vargas underwent major hip surgery last season. But Vargas said his hip feels fine, and he is ready to go whenever the Mariners need him.

"As a starter, that's always what you envision, to be a guy that they can count on and kind of really rely on you to go out there and have a good outing," Vargas said. "Especially with the close division that I think it will be the entire year."

Pitching matchup
SEA: LHP Jason Vargas (2-2, 3.56)
The left-hander was going to get two extra days between starts, but Bedard's DL trip scrapped those plans. He has struggled a bit in his last two outings, which prompted the idea of getting some extra rest. Vargas has a terrific changeup, but didn't use the pitch often enough in his start against the Rockies and was rocked during a five-run fifth inning.

ARI: RHP Billy Buckner (2-3, 7.36 ERA)
Buckner is looking for his second victory of the month and hoping to rebound from two consecutive subpar starts. In his last start, Astros shortstop Miguel Tejada hit an RBI double off Buckner for the visitors' first run of the game in the first inning, and Lance Berkman followed with a two-run home run to extend the Astros' lead to 3-0. Buckner was eventually charged with six runs on five hits in five innings for the loss. In his previous start against the Giants, he was charged with eight runs and 13 hits in 5 2/3 innings for the loss. He has been plagued with poor execution of his pitches, but is confident he can bounce back in his next start.

Tidbits
Seattle catcher Rob Johnson was activated from the bereavement list on Friday. ... Catcher Guillermo Quiroz was designated for assignment. ... Bedard underwent an MRI and should be able to resume throwing in three days, but won't be available until Seattle's June 30 series against New York at the earliest. ... The Mariners claimed infielder Josh Wilson off waivers Friday. ... Catcher Kenji Johjima will catch five innings and get two at-bats at Triple-A Tacoma on Saturday. ... Injured reliever Shawn Kelley will throw on the side on Saturday, pitch a simulated game on Tuesday and throw a bullpen session on Thursday.

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Up next
• Sunday: Mariners (Felix Hernandez, 7-3, 2.77) vs. Diamondbacks (Doug Davis, 3-8, 3.72), 1:10 p.m. PT
• Monday: Off-day
• Tuesday: Mariners (Garrett Olson, 2-1, 4.30) vs. Padres (Chad Gaudin, 2-6, 5.98), 7:10 p.m. PT