Professor Brian Cox has been "roped in" to take part in the Monty Python reunion concert, Eric Idle said.
The star said he wanted Cox to join in on a performance of Galaxy Song from The Meaning of Life. Speaking after today's press conference, Mr Idle said:
"John can't do silly walks because he has a hip replacement, I decided I couldn't do the Travel Agent because you have to talk for 15 minutes and it's really exhausting and so I thought well I'd like to do some of the songs we've never done.
"I'd like to do Galaxy Song with Professor Brian Cox coming in. I was with him last night, talked him into it."
The remaining members of Monty Python have announced four more shows after their reunion at London's O2 sold out in less than a minute.
The five remaining stars of the internationally acclaimed comedy troupe are to perform together in a live show at the O2 Arena in London.