Larsson's current deal runs out in June and McLeish admits other players he has worked with entitled to leave on a Bosman transfer have "downed tools". But McLeish insists Larsson's approach has never changed and he scored the opening goal in Saturday's 2-0 win over Sunderland at St. Andrew's.
McLeish said: "We were close to losing Seb in January but I didn't want him to go. That boy has restored my faith in players because I have seen players before on a Bosman put their tools away."
He added: "He has defied that and done magnificently. I can't speak more highly of the guy.
"He has not only been a top quality player but his attitude and commitment to the cause has been first class.
"He has been a revelation. This guy has gone right up in my estimation.
"What a hero he is for the Birmingham cause."
McLeish is still hoping Larsson will sign a new contract with Blues and extend his five-season spell.
He said: "Seb said to me he has not made up his mind and he has not ruled out staying.
"He told me that to my face the other day."
Source: PA
Source: PA