Durant added 11 points including a 3-3 mark from three before entering Golden State's locker room in the second quarter.
The 2017 and 2018 Finals MVP was declared out for the rest of the contest after he entered Golden State's locker room. Durant left Scotiabank Arena in the third quarter while on crutches.
Durant will receive an MRI on Tuesday, though the Warriors fear the MRI will reveal a torn achilles, per ESPN's Ramona Shelburne and Adrian Wojnarowski.
Durant limped to Golden State's locker room following the injury with the help of teammate Andre Iguodala. His status for the rest of Game 5 has yet to be announced.
Durant has not played for Golden State since injuring his calf against the Rockets on May 9. He tallied 11 points before his injury including a 3-3 mark from the field.
The Raptors now lead the series 3–2, and Game 6 will be at Oracle Arena on Thursday at 9 p.m. ET.