Houston Rockets coach Mike D'Antoni remains uncertain of when or if All-Star guard Russell Westbrook will be available during the team's first-round series against the Oklahoma City Thunder.

D'Antoni said before Tuesday's 123-108 Game 1 win that Westbrook's strained right quadriceps is healing, but the team does not have a specific timetable for his return.

"Can't rule anything out, but don't rule anything in," D'Antoni said.

Westbrook was scheduled to undergo an MRI on Tuesday, and the results were not immediately known.

Westbrook, who was a late arrival to the NBA's Walt Disney World Resort campus because he tested positive for COVID-19, felt soreness in his right quadriceps after the Rockets' loss to the Portland Trail Blazers on Aug. 4. He sat out the next two games because of a right quad contusion, according to the team.

Westbrook played 28 minutes in Houston's Aug. 11 loss to the San Antonio Spurs, recording 20 points, 5 rebounds and 6 assists. The Rockets announced the next day that an MRI had revealed that Westbrook had a strained muscle in his quad.

A nine-time All-Star acquired in a blockbuster trade with the Thunder last summer, Westbrook has averaged 27.2 points, 7.9 rebounds and 7.0 assists per game in his first season with the Rockets.