He wasn't able to practice with his teammates, but the 30-year-old hopes to get back on the field as soon as possible.
"Luckily we have a long week to give it some time to heal...we'll see where we are in a couple of days," Durant told reporters after practice.
Durant left Thursday's 39-28 win over the Toronto Argonauts in the fourth quarter. An MRI revealed the sprain the next day.
Saskatchewan takes on the Hamilton Tiger-Cats in Regina on Sunday night. If Durant is unable to play, Drew Willy will start in his place.
Durant has passed for eight touchdowns so far this season, leading the Roughriders to a 3-0 start.