The AJ can also reveal that Alsop's enthusiasm for the role is not about reigning in Richard Rogers' power - but more about blocking a potential bid for the role from Ricky Burdett, currently Ken Livingstone's architecture advisor.
Alsop told the AJ he is determined that Burdett's brand of urbanism should not hold any more sway in the capital.
It is unclear whether reports of AR editor Paul Finch's involvement in a joint application for the role hold any water.
But what is clear is that McColl - whose firm SMC recently bought Alsop's practice - is keen for his underling to take on the role.
'I am encouraging Will to go for it,' McColl told the AJ. 'I think he is definitely the best man for the job.
'I'd also be keen as it would increase his profile even further.
'This is not about whether Will will have the time. Some people work 37-hour weeks; I always say Will works a 37-hour day.
'He's always up to something,' McColl added.