Aston Villa captain Stiliyan Petrov is determined to fight acute leukaemia "head-on", according to Alex McLeish.
The Villa manager accompanied Petrov and his wife Paulina as the player began his treatment for the illness at a London hospital on Monday.
"Randy Lerner [chairman], Paul Faulkner [chief executive] and myself went to see Stiliyan on the first day of his road to recovery," said McLeish.
"He's determined to meet it head on - we expect that from Stan."
Petrov's initial treatment involves taking a course of steroids and tablets which will prepare him for chemotherapy.
Earlier, his ex-Celtic team-mate John Hartson, a former cancer sufferer who beat the illness in 2009, said the Bulgarian international was "upbeat" as he prepared to start his treatment.
"A lot of it is psychological. You have to get your head around what is happening and dealing with it as openly as you can," Hartson, who was diagnosed with testicular cancer before the condition spread to his lungs and brain, told BBC Scotland.
"You do know there is a lot of support out there when you are battling a near death experience like I went through.
"Stiliyan knows he has support from his peers and his family, which will be very important for him.
"He's very strong. His fitness, I'm sure, will help him. He knows he has so much support from throughout football."
Fifa president Sepp Blatter has wished Petrov "strength in his fight to win this battle" via Twitter.
Blatter added: "[I am] very sad to hear about Stiliyan Petrov's illness. The support shown at Villa Park by both sets of fans another sign of all that is good in football. #getwellstan."
Petrov watched Saturday's defeat by Chelsea from the stands and stood to acknowledge an ovation from both sets of supporters in the 19th minute, timed to match the player's squad number.
McLeish revealed Petrov addressed the Villa squad before the match, vowing to beat the condition.
Striker Andreas Weimann, who made his first Premier League start in the match, said the squad was shocked to hear about his illness.
"Everyone at the club is devastated but we are all behind him," Weimann told the club website.
"He's ready to fight it and hopefully he'll get through it.
"He came in before the game, said hello to the players and wished us all the best, and that was brilliant from him."