McLaren: James Key to start next month after move from Toro Rosso
James Key is to take up his new role as McLaren technical director on 25 March after the team reached a deal with his former employer Toro Rosso.
McLaren signed Key last July but the 46-year-old was still under contract to Red Bull and could not start work.
He will now be in place in time for the second F1 race of 2019, the Bahrain Grand Prix on 28-30 March.
Toro Rosso have promoted deputy technical director Jody Egginton to Key's former role.
Key is the latest recruit in a major restructuring at McLaren that began last spring when it became clear how far behind the team had fallen in chassis performance.
Two of the three men who had led the design department left in 2018 - chief technical officer Tim Goss and engineering director Matt Morris - in addition to racing director Eric Boullier.
Brazilian former Indycar champion Gil de Ferran joined as sporting director in July and Pat Fry rejoined as engineering director in September. Fry had worked for McLaren from 1993-2010 before joining Ferrari, from where he was fired at the end of 2014.
And German Andreas Seidl will join McLaren as managing director on 1 May to oversee the F1 team under chief executive officer Zak Brown.
Seidl is the former boss of Porsche's successful world endurance championship team.