Michael Andretti is due to drive the car and if engineers are satisfied with its performance in rudimentary runs, it may be put through its paces in at least part of next week's major test, at Estoril.
The team are expected to confirm an engine deal with Ford and the signing of the Finnish driver, Mika Hakkinen, having successfully argued before the Contracts Registration Board that Lotus had no binding agreement with him. Lotus have already named the Italian, Alessandro Zanardi, as Hakkinen's replacement.
McLaren may not, however, be able to reveal how many appearances Hakkinen will make in the championship. They are still hoping to persuade Ayrton Senna to play a role, but he wants to see the car before committing himself. The Brazilian, who last year offered his services to Williams 'for nothing' is also said to be demanding dollars 5m ( pounds 3.5m) more than the dollars 15m McLaren are offering.
Senna might even delay his decision until after the first race, in South Africa on 14 March. He could choose to limit his exertions to test work for Ferrari, ahead of a lucrative racing contract with them in 1994, or simply take a year off.
Another driver who may race for McLaren at some stage or stages is Britain's exiled world champion, Nigel Mansell, currently preparing for his maiden IndyCar series. If both he and Andretti become disenchanted with their respective new worlds, or their respective new worlds become disenchanted with them, a straight swap would be an obvious solution.
A further, intriguing theory is doing the Formula One rounds: if Fisa refuses Alain Prost a super- licence for criticising the stewardship of the sport, Senna could yet get the job he wanted all along - with Williams.