The team held a five-on-five scrimmage to give him his first full-speed action since he got hurt, ESPN's Tim McMahon and Adrian Wojnarowski reported.
A Rockets source said Westbrook looked as "explosive as ever."
Westbrook—who averaged 27.2 points, 7.9 rebounds, 7.0 assists and 1.6 steals per game during the regular season—has missed multiple games with the injury.
While Houston's offense is predicated on open threes and shots at the rim, that gets considerably tougher without the UCLA product in the lineup.
He is still one of the most explosive guards in the NBA, and his ability to fly down the lane and create high-percentage scoring chances makes him one of the keys to the team's success.
With Westbrook out for the playoffs so far, the Rockets find themselves tied with the OKC Thunder at two games apiece in the first round. Game 5 is scheduled for Saturday at 6:30 p.m. ET.