Baltimore manager Dave Trembley said X-rays on Roberts came back negative.
"We'll see how it is [Sunday]," Trembley said. "He took a direct hit right there, and he was sore. He couldn't go. He wanted to go, but he couldn't do it."
In the game's opening at-bat, Roberts swung at a 2-1 fastball from Jays left-hander Brett Cecil. The switch-hitting Roberts was batting right-handed and fouled the ball off his front leg.
Roberts visibly was in pain, but he stayed in the game and drew a walk. Roberts went out on the field to play second base in the first and second innings, but he was replaced by pinch-hitter Robert Andino in the top of the third.
"Got this one pretty good," Roberts said. "Usually they don't swell up on me. This one did.
"I was getting worse and worse, and I figured I should get ice on it right away."
Roberts, who walked with a slight limp after the game, has started 106 of Baltimore's 110 games at second base. Ty Wigginton, who pinch-hit for Andino in the ninth inning and stayed in the game, started the other four.
Roberts has a .282 batting average and a .350 on-base percentage as the O's leadoff hitter.
Erika Gilbert is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.