Santos threw 18 pitches in one Minor League inning and didn't report lingering soreness the following day.
"I don't foresee anything why I shouldn't be ready for Opening Day," Santos said. "If Opening Day was next week, I feel like I would be ready. So from my standpoint, the way I see it now, I feel like I am 100 percent ready moving on from here."
Santos threw fastballs and changeups in his Minor League outing. Sliders are expected to be added back into the mix during a scheduled outing vs. the Orioles on Saturday.
The goal is for Santos to throw back-to-back outings at some point late next week and possibly have a two-inning outing later this spring. The combination of those tasks should put him in an ideal situation to start the year.
One of the final hurdles is finding a way to master his changeup. It's a pitch Santos didn't throw very often with the White Sox, but it had become a top priority last year until a right shoulder injury brought his first season in Toronto to an abrupt end.
"When it's not going the way I want, it's probably not moving or biting down," Santos said of the changeup. "It's a little harder than most changeups, but I'm OK with it as long as my movement is there.
"What I'm hoping it's going to do is give me some groundballs, some double plays, something that I can help minimize pitches and throw it early in the count, and hopefully some of these guys put it in play and put it in play softly."
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.