Sebastien Buemi was given the all-clear after crashing at high-speed during a Pirelli tyre test with Red Bull at Silverstone.
After last weekend’s British Grand Prix, the Anglo-Austrian team along with Williams stayed behind to conduct two days of development work with the Italian tyre supplier for next season.
It has since emerged that the Swiss, who remains a Red Bull reserve driver while racing in Formula E and WEC, ended Wednesday’s action early after hitting the barriers at Abbey.
The team confirmed via Motorsport Week that an investigation into the crash was ongoing and that Buemi had been released from the hospital after a “thorough medical examination”.
During the two days of running, Williams had opted to use both race drivers, Robert Kubica and George Russell, while Pierre Gasly had driven the RB15 on Tuesday.