Mark Ellis and Giles Wood will join Mercedes AMG Petronas from Red Bull Technology.
Lotus is still working to make 2014 simulator as accurate as possible.
Ross Brawn hopes to return to F1 after a sabbatical.
Niki Lauda claims Ross Brawn will return to Formula One.
Martin Whitmarsh said the rumours Mercedes will lead the game in 2014 cannot be verified.
Schumacher admitted he is worriedly watching the situation from the sidelines.
Ross Brawn will formally leave the team on 31st December 2013.