Havenstein wasn't activated from the reserve/COVID-19 list and won't be available for Tuesday's game against the Seahawks, Lindsey Thiry of ESPN.com reports.
Even after the NFL pushed back the Week 15 contest two days due to COVID-19-related concerns within the Rams organization, Havenstein is one of three starters and nine members of the 53-man roster who wasn't cleared to return from the list prior to Tuesday's 7 p.m. ET kickoff. Joe Noteboom started in place of Havenstein at right tackle in the Rams' Week 14 win over the Cardinals, but Los Angeles will have to break in a new option at the position Week 15 after Noteboom wasn't activated following his placement on the reserve/COVID-19 list Saturday.