Williams co-founder Sir Patrick Head has returned to the team as they try to recover from a sobering start to the new season.
The 72-year-old is working on what Williams describe as "a short-term consultancy basis".
Alonso's McLaren team finished sixth in last season's constructors' championship
Fernando Alonso is to test for McLaren in Bahrain next week in his role as adviser to the team.
The two-time champion, who left Formula 1 at the end of last season, will drive for two days at the official F1 test after this weekend's grand prix.
Mick Schumacher will drive for Prema in his first Formula 2 season
Mick Schumacher, son of seven-time champion Michael, will make his Formula 1 test debut for Ferrari on 2 April.
The 20-year-old German, who signed up to the Ferrari driver academy over the winter, will drive for them and the affiliated Alfa Romeo team in Bahrain.
Winning tastes good - only the fourth time in his F1 career Bottas has sampled it
Valtteri Bottas dominated the season-opening Australian Grand Prix after overtaking world champion team-mate Lewis Hamilton.
The Finn took the lead at the start from Hamilton, who made a slow getaway from pole position, and even took the new bonus point for the fastest lap.
The Bahrain Grand Prix was first staged in 2004
F1 chiefs say they will "continue to investigate" alleged human rights abuses in Bahrain.
Representatives met with campaigners on Wednesday to discuss Najah Yusuf, who was jailed two years ago.
