In his final Cactus League tuneup for his Opening Day start in Minnesota on Monday, Weaver yielded one earned run on six hits across six innings on Wednesday at Tempe Diablo Stadium in a 7-5 loss to the Cubs.
Weaver didn't walk a batter and struck out five, ending the spring with a 5-0 record and 1.37 ERA while walking three men and striking out 19 in 26 1/3 innings.
He hadn't yet been given formal word of his assignment in the opener against the Twins by manager Mike Scioscia, but Weaver maintained that he would feel no added pressure assuming the No. 1 role with John Lackey (strained right triceps) and Kelvim Escobar (tear in right shoulder) sidelined indefinitely.
"I know what they're going through," said Weaver, who opened the 2007 on the disabled list in recovery from biceps tendinitis. "It's not what you're looking forward to. I don't feel greater responsibility. We've got five [starters] who are going to compete just like I do.
"I don't feel any weight on my shoulders. [I will] just go out and keep doing what I'm doing and see what happens."
Scioscia said he might have the rotation set up on Thursday. "We're confident whatever direction we go, we're going to have a good rotation."
Weaver was dominant in the Cactus League, consistently putting his fastball, slider and changeup in good locations. He focused on fine-tuning his offspeed stuff against the Cubs, and while he wasn't satisfied with his slider, he did enough to keep the hitters off-balance for the most part.
Asked about defending the American League West title with a diminished pitching staff, Weaver said: "It's going to be a battle to start off, that's for sure. We didn't imagine starting with our two horses out, and with [Gary Matthews Jr.], we don't know how bad his [sprained right] ankle is. But we've got a lot of depth."
As for pitching the opener, he said it would be a "tremendous honor. At the same time," he added, "it kind of stinks that the two horses are down. They'd be battling for the top spot."
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.