Rob Smedley is finally starting work at Williams.
More than a month ago, the British team confirmed long speculation the 40-year-old Briton, famous for his close relationship with Felipe Massa at Ferrari, will soon become 'head of vehicle performance' at Grove.
Brazil's Globo said Smedley has now served his mandatory gardening leave and will be on the pitwall in Bahrain.
"Rob will be at the track and I will work in the factory and at the tests throughout the season," Williams' chief engineer Rod Nelson is quoted as saying.
"He will bring a lot of experience and a lot of good ideas," Nelson added.