Keene (knee) was placed on the reserve/COVID-19 list Monday, Aaron Wilson of Sportstalk 790 Houston reports.
Keene underwent season-ending surgery to repair a meniscus injury in August and isn't expected to play this season. However, after being placed in COVID-19 protocols following his positive test, he will have to produce back-to-back negative tests at least 24 hours apart or complete a 10-day quarantine (if unvaccinated) before he's able to return to team facilities.