Saunders tore cartilage Wednesday when he stepped on a sprinkler while shagging fly balls on a side field at spring training. He was originally projected to be out until mid-July.
Blue Jays general manager Alex Anthopoulos said that Saunders could be sidelined only five to six weeks.
"We'll see how he recovers," Anthopoulos said. "The fact that he's going to walk out of there (the operating room) today is great, and he'll be running hopefully somewhat soon."
"Once we get him into games, then it will just be a matter of timing and how many at-bats he's going to need," he said.
Anthopoulos said after doctors assessed how significant the tear was, there was no other choice than to partially remove the damaged cartilage.
"Doctor told me everything else looked great in his knee and 40 percent cartilage is still a good chunk," Anthopoulos said. "I think down the road, years from now, maybe it's something he's going to have to be on top of. ... But it wasn't even an option to get it repaired."
The 28-year-old Saunders hit .273 with eight home runs and 34 RBIs in 78 games with Seattle last season. He was acquired by the Blue Jays in December for pitcher J.A. Happ, and Toronto planned on him being a starter.