Sources: Houston Rockets' John Wall, DeMarcus Cousins sent home as team traces COVID-19

Although John Wall and DeMarcus Cousins tested negative for the coronavirus on the morning of the Houston Rockets' season opener on Wednesday, they could still be absent for the start of the team's season, sources told ESPN.

Contact tracing protocols caused the Rockets to send home three players Wednesday after rookie teammate Kenyon Martin Jr. returned a positive coronavirus test and needed to be tested again for confirmation, sources said.

The league announced later Wednesday that the Rockets' game against the Oklahoma City Thunder was postponed.

Wall, Cousins and Martin were among Rockets players gathered on Tuesday evening at a player's apartment away from the team facility getting haircuts, sources said. The Rockets listed Martin as "not with the team/self isolating" for the opener against Oklahoma City on Wednesday night in Houston, and sources told ESPN that he was awaiting further test results to confirm the original positive.

Rockets rookie Jae'Sean Tate is also among the players who were sent home Wednesday morning because of contact tracing, sources told ESPN.

The NBA's new protocol on contact tracing gives the league the ability to make decisions on possible timelines for return if players continue to test negative.

The Rockets already had one player, Ben McLemore, away from the team for a few days with the coronavirus, sources said. And the NBA is investigating whether Rockets star James Harden violated league protocols based on a video circulating in recent days.

The Thunder had not been immediately informed on the status of any Rockets players, or Wednesday night's game, sources said.

Martin was self-isolating at his hotel, and so far not feeling any typical coronavirus symptoms, sources said.

ESPN's Bobby Marks, Tim Bontemps and Tim MacMahon contributed to this report.