The Aston Villa manager pays tribute to the Bulgarian midfielder as he sets out to battle acute leukaemia and says he is in fantastic spirits despite the life threatening illness
The 32-year-old midfielder began his treatment on Monday with his family and club representatives by his side.
Speaking to Sky Sports News McLeish said: "The chairman Randy Lerner, the chief executive Paul Faulkner and myself went to see Stilian today with the support of his wife, on this the very first day of his road to recovery.
"He's determined to meet it head on. We would expect that from Stan, and he was talking really positively and actually couldn't wait to get started, to try and clear up this illness that he has.
"The support he has had from football friends here at Aston Villa, Celtic yesterday and the Chelsea players on Saturday afternoon, we are really delighted and proud of the response from the football family.
"Stan himself is in amazing spirits, absolutely fantastic spirits. God knows what the lad is probably thinking in his head, but he is the captain of Aston Villa and he has shown commitment on the pitch, he is a pure leader and he wants to lead himself through this particularly tough time."
When asked whether it was too soon to think about the long-term, McLeish added:"I think it's too early to think about that. He faces a battle, he will stand up to that battle and this afternoon he is talking about coming back to training tomorrow because he thinks he can train, that's the kind of spirits he's in.
"Everyone's here to support him. We thought it was appropriate that we should be there with him on his very first day towards recovery."
McLeish also called for Petrov's privacy to be respected, so that he and his family could given the time and space required at this difficult time.
"We want to be guided by Stan and his wife Paulina and we will do their bidding - whatever Stan wants.
"We realise there will be a lot of people clamouring to speak to him and I'm sure at some stage he will want to give a few words himself. I know the Bulgarian nation are supporting him really strongly also, and I'm sure in his home country they would like to talk to him as well.
The Scott added:"We are making this statement today because he is going to go through a battle now and there won't be daily bulletins. We will update you when we feel it is appropriate on behalf of Stilian Petrov and his family."