Alex McLeish had a glass of chardonnay in his hand when he suggested over lunch on Wednesday that he might “feel like heading for the nearest bridge” at about 5pm today. But he was defiant about the decision he made to resign as Scotland coach last November, taking up the challenge of keeping Birmingham City in the Premier League.

“I have no regrets about leaving the Scotland job and I came here with my eyes open,” he insisted. “People told me it was one of the hardest jobs in football, so why should it be any easier now?”

The mathematics are simple: to avoid relegation to the Championship, Birmingham must achieve a better result against Blackburn Rovers than Fulham are able to secure at Portsmouth and Reading at Derby. With their superior goal difference, a draw will be enough if both of their rivals lose.

“There was a short-term goal for me when I arrived at St Andrews and it is still there for us,” McLeish emphasised. “We can still stay up and I’m still positive about that. There is no such thing as a ‘sure thing’ and, although we know that people have already written us off, I see this game as an opportunity. We are still in with a fighting chance.”

Despite concerns about the fitness of striker James McFadden and defender Liam Ridgewell for today’s match, the manager has several reasons for optimism. During McLeish’s 23 league games in charge, Birmingham have lost only once at St Andrews, by a single, late goal against Chelsea in January. They are unbeaten in their past seven home matches. Argentine forward Mauro Zarate, a 21-year-old on loan from Al-Sadd in Qatar, has shown outstanding potential and Sebastian Larsson, the 22-year-old Swedish international midfielder who was signed from Arsenal last season, is emerging as one of the best young players in the Premier League.

“Larsson’s general work down the right side has been invaluable,” Trevor Francis, the former Birmingham striker, said recently. Dropping into the Championship could force McLeish to sell Birmingham’s best player, a possibility at which Larsson hinted last week. “Obviously, the Premier League is where I want to be and I want nothing more than to be in the Premier League with Birmingham,” he said. “I don’t think that any of our players want to go back and play in the Championship. I haven’t even thought about that or what would happen if we went down but I’m extremely happy here, I’m contracted to Birmingham [for another two years] and there’s nothing more I can say about this.”

It was only when he left St Andrews and became British football’s first £1m player that Blues legend Francis enjoyed some tangible success in his career, which included scoring the winning goal in the 1979 European Cup final for Nottingham Forest against Malmo. He still attends as many Birmingham games as he can and the fact that today’s game is at home gives him hope.

“There are two Birmingham teams and the one that plays away from home is bordering on disaster,” he declared. “I was at the Aston Villa game [a 5-1 defeat at Villa Park], my son was at Craven Cottage last weekend [a 2-0 win for Fulham] and he told me all about that. Both performances appear to have been on a similar level, totally lacking in passion and fight and determination, but Birmingham City are still a difficult team to play against at St Andrews, when they have that fervent backing of a hostile crowd.” McLeish hopes that the atmosphere generated by Birmingham supporters today will inspire his team, but he is prepared for whatever eventuality. “In the six months after leaving Rangers and before the start of [Scotland’s] World Cup campaign I had my comfort zone, going to Dubai on holiday with the missus, being a professional supporter and watching games at home and abroad and there was no pressure. But I like a challenge in my life and I saw this as an opportunity, not a threat, and I still see it that way,” he said.

“I am used to winning and this is why I have belief that I can be successful here, whether that means this year, next year or the year after. I have to prove that I can be a success at Birmingham.

“If the worst were to happen, I still have a long-term plan. You don’t build a team overnight and it doesn’t happen in six months either.”