Per Yahoo Sports' Chris Haynes, Durant "was not anywhere close to 100 percent" after missing one month with a strained right calf.
ESPN.com's Ramona Shelburne and Adrian Wojnarowski reported the Warriors believe Durant's MRI will reveal he tore his right Achilles tendon in the second quarter Monday.
McCollum and the Blazers Snapped Postseason Losing Streak for "Jennifer"
Stars Invest in Plant-Based Food as Vegetarianism Sweeps NBA
The NBA Got Some Wild Techs This Season
Jarrett Allen Is One of the NBA’s Hottest Rim Protectors
Wade's Jersey Swaps Created Epic Moments This Season
Westbrook Makes History While Honoring Nipsey Hussle
Devin Booker Makes History with Scoring Tear
29 Years Ago, Jordan Dropped Career-High 69 Points
Bosh Is Getting His Jersey Raised to the Rafters in Miami
Steph Returns to Houston for 1st Time Since His Moon Landing Troll
Lou Williams Is Coming for a Repeat of Sixth Man of the Year
Pat Beverley Has the Clippers Stealing the LA Shine
LeBron Keeps Shredding NBA Record Books
Young's Hot Streak Is Heating Up the ROY Race with Luka
LeBron and 2 Chainz Form a Superteam to Release a New Album
Wade's #OneLastDance Dominated February
Warriors Fans Go Wild After Unforgettable Moments with Steph
Eight Years Ago, the Nuggets Traded Melo to the Knicks
Two Years Ago, the Kings Shipped Boogie to the Pelicans
ASG Will Be Competitive Again If the NBA Raises the Stakes
Haynes noted "Durant fought valiantly to push up his return date" because he wanted to get back on the court to help Golden State in its quest for a third straight championship.
The Warriors continued to offer vague updates on Durant's availability for the first four games against the Toronto Raptors. Things changed Sunday when Haynes reported the 10-time All-Star would be cleared for practice.
Head coach Steve Kerr told Kristen Ledlow of NBA TV prior to Game 5 that the team would go by how Durant felt rather than put a minutes restriction on him.
Durant looked like his usual self out of the gate. He went 3-of-3 from three-point range and scored 11 points in 12 minutes before the injury. It was his first game since he strained his calf May 8 against the Houston Rockets.
The Warriors held on to win 106-105 on Monday to force Game 6 at Oracle Arena. Another win Thursday will lead to a decisive Game 7 on Sunday in Toronto.