"It started a couple of days ago when I took a swing and felt it. It has been kind of painful for swings. It is just a part of the season," Betts said. "It's a sharp pain. I can't really move my hand for a little bit. I don't really know what's going on. We'll find out tomorrow."
Red Sox manager John Farrell came out with a trainer to check on Betts, who was holding onto his left wrist.
Betts remained on the basepaths and returned to right field after the inning ended but was pinch-hit for by Andrew Benintendi, who belted an eighth-inning solo home run to cut the Blue Jays' lead to one.
"He might have had a little bout of it that would fade at times," Farrell said. "After the one swing, he felt like it was a little bit more intense there, and we took him out precautionary here tonight."
Betts went 2-for-3 with two RBIs, increasing his season total to 101.
Betts has battled bumps and bruises throughout the season, including thumb and foot injuries in the past couple of weeks. The Red Sox outfielder was confident that this matter wouldn't keep him away from the American League East pennant race.
"I'm not really that concerned," Betts said. "I think it will be fine. … I have to come in every day ready to play and then go from there. We haven't won the division yet. We have to go out and continue to strive for that."
Craig Forde is a contributor to MLB.com based in Boston.