And Mourinho insisted afterwards he did not believe Duff was ready for his international call-up.

But Kerr has detected no problems with Duff’s fitness approaching the final friendly before next month’s opening World Cup qualifier against Cyprus.

Kerr said: “Damien has looked fine and he will start. It’s the last friendly and I want to be getting nearer to the team that’s going to play against Cyprus.

“We won’t abuse the fact that the clubs have been more than co-operative with us with regard to the release of players because I really respect that.

“As yet I haven’t had any calls from clubs and I’d like to think it’s because people say that we’ve been all right with them.”

Manchester City striker Jonathan Macken will be handed his Ireland debut after finally being given clearance by FIFA.

Macken and the Football Association of Ireland finally won their battle to have his solitary England youth appearance seven years ago scrubbed from the record.

Macken subsequently discovered grandparents were from Co Cavan and has decided to commit his future to the Republic.

He said: “I’ve waited a long time for this and now I want to prove I deserve a place in the side. It’s a very special occasion for me and my family. My grandfather passed away during the summer and it is a shame he is not here to see it through.

“I know he would be very proud that I will going out there to represent Ireland.”

Alan Lee is the only late doubt for Kerr as he missed Tuesday training with a cricked neck.

June’s friendly win in Holland has maintained good spirits in the Irish camp approaching the crucial qualifying double-header against the Cypriots and previous nemesis Switzerland.

Captain Kenny Cunningham believes the squad has long since bounced back well from the disappointment of missing out on a summer in Portugal.

Cunningham insisted the shock success of Greece at Euro 2004 ought to serve as inspiration that there be no limits to Irish ambitions.

Cunningham said: “Certainly the success of Greece has given the so-called smaller nations encouragement and hope.

“It just shows you that if you are organised as a team, totally committed and have a good spirit there is no limit to what you can achieve.

“Those are traits that have been spoken about in our team for a number of years so that gives us great encouragement going into the qualifying campaign.”

Kerr’s men prepare to come up against one of Europe’s most inconsistent teams tomorrow.

The visitors are rebounding from a dismal Euro 2004 and have the considerable incentive of wanting to impress national hero Hristo Stoichkov, who takes charge as coach for the first time.

Kerr admitted he was not entirely sure what to expect from Stoichkov’s team. “Bulgaria are a very good team – we noted their defensive deficiencies during Euro 2004 but they had conceded only four goals in qualifying before that," he said.

“There is a bit of a contradiction there. I wouldn’t be surprised if they have a real go at us tomorrow.

“They will want to prove a point and get in shape for their own qualifying group.”