Sanchez suffered the injury on his pitching hand, according to Sportsnet's Ben Nicholson-Smith.
Following the Blue Jays' 5-4 win, manager Charlie Montoyo said the team is hopeful Sanchez won't have to miss a start, according to Nicholson-Smith.
Sanchez threw 59 pitches before his exit, allowing two hits, an earned run, and three walks in four innings.
The issue is a familiar one for the 26-year-old, who's only made 28 starts over the past two seasons due to finger problems.
Sanchez had been pitching well entering Sunday, posting a 2-1 record with a 2.86 ERA and 4.42 FIP in 22 innings.
The potential loss of Sanchez would test Toronto's starting pitching depth. The Blue Jays placed Matt Shoemaker on the 10-day injured list Sunday with what was later revealed to be a season-ending ACL tear and were already operating without Clayton Richard and Ryan Borucki, both of whom are out with injuries.