Houston's rotation is a question mark after Oswalt, with Woody Williams, Wandy Rodriguez, Brandon Backe, Chris Sampson and Shawn Chacon in the mix. Backe is coming off elbow surgery, and Williams' first season in Houston was one to forget with a 5.27 ERA and 8-15 record.
"We have some guys that don't have the track record but have the stuff to do this," Oswalt said. "We also have a veteran guy in Woody. He's done great. He had one bad year and everyone's counting him out. I don't think it should be that. We've got a good enough staff to get it done."
Felipe Paulino, another pitcher who could factor in the rotation, went back to Houston on Monday afternoon to see a doctor about discomfort in his upper right arm. He's allowed four hits and five runs in two outings this spring.
The Astros hoped to get Oswalt up to 75 pitches, but he left after 70. He finished with three strikeouts and said he felt good and could have gone longer. He has three more starts this spring and hopes to get his pitch count up to 90 in the next one and 100 two games from now.
"Roy looked sharp," Astros manager Cecil Cooper said. "It was probably his best outing this spring. He threw well."
The Blue Jays got four innings and five strikeouts from Halladay. He allowed three runs and six hits, including a homer to Lance Berkman.
Halladay thought his performance was OK, but he was happy to get acquainted with new catcher Rod Barajas. Monday was the first time Barajas had caught for Halladay.
"We just did some different things and some of them didn't work," Halladay said. "It's kind of a learning experience. The last two innings were a lot better than the first two."
Barajas said he was so excited he was "like a little kid" when he learned a couple of days ago that he'd be catching Halladay.
"Every time you change teams you've got to learn," he said. "This was the first step in getting familiar with Roy."
Berkman's home run to center field off Halladay came in the first inning and was his first of the spring. Berkman also hit his first triple off Halladay in the third. Berkman tweaked his leg running on a double in the eighth, but Cooper said it wasn't serious and he should be fine.
Stephen Randolph pitched a scoreless inning for the win.
Hector Luna, Adam Lind and Barajas each had an RBI for Toronto.
Notes: Astros 2B Kazuo Matsui was in Houston on Monday to see a doctor about a health problem that has been bothering him for most of spring training. He was diagnosed with an anal fissure and his medicine to treat the problem was changed. He was expected to return to Florida on Monday night. He'll hit and throw at Houston's complex for four or five days before returning to games.