Ever the professional, Giovanni Trapattoni has refused to allow his Ireland team to celebrate Euro 2012 qualification before the final whistle blows in the second leg of their playoff on Tuesday. Ireland take a surprise 4-0 lead into the home tie, following their comprehensive victory in Tallinn last Friday when the hosts had two players sent off. The country is already excitedly looking ahead to next summer's European Championships in Poland and Ukraine, but veteran Italian manager Trapattoni would concede he is only "51 percent" sure of qualification, despite the fact he has never surrendered a four-goal advantage in all his years in management. "I am very, very happy, but I will wait, I will celebrate when we can make the celebration. Now, I am 50 percent...or 51 per cent. It's not 100 percent," Trapattoni said Sunday. Trapattoni is wary of disrespecting Tarmo Ruutli's men, who will travel to Dublin without both red card recipients, defender Andrei Stepanov and captain Raio Piiroja, as well as goalkeeper Sergei Pareko, suspended after the yellow card he received for protesting after Ireland won a late penalty. Stephen Kelly will miss out for Ireland after sustaining a groin injury on Friday but, such is the strength of the Irish squad, Sunderland's John O'Shea will step in. Damien Duff is expected to shrug off a rib injury to play, while Wolves' Kevin Doyle will return after suspension, with Jonathan Walters, who scored the second goal on Friday, benched. "It's not sporting to underestimate a rival," Trapattoni warned. "I want the players to understand that we are playing in Dublin and we want victory for the fans because people who pay for tickets are expecting a performance from us. "They wait for our result and we cannot betray them. "I said to the team that we have the duty to repeat the same game (as Friday), maybe not the goals, but we need to be careful, it's not easy. "This is another 90 minutes, and while our opponent lost a little pride, it's important to play this game with the same seriousness. Perhaps we can play with more confidence because of our advantage." Ireland's first legwin has made it all but certain Trapattoni will be offered a new contract by the Football Association of Ireland (FAI), even though he is 72, with the governing body having said they would await the outcome of the playoffs to decide his future. Trapattoni has been in charge since 2008, and made no secret of his desire to extend his stay and lead the country to the 2014 World Cup. After missing out cruelly on World Cup 2010, following a heartbreaking playoff defeat by France, and all but securing qualification this time around, the Italian's hand is particularly strong. "I do not wish to put pressure on FAI," Trapattoni said, safe in the knowledge the federation has little option but to back the man who has now virtually taken the Republic to their first major tournament since 2002. "I am happy to stay, because not only do I believe in these players, but I am convinced we have a good team and the team can improve." Should Ireland seal the deal, they hope to arrange a warm-up game against England, 1-0 winners over world champions Spain last weekend, in 2012, Trapattoni revealed. "We have spoken with them (England's Football Association) for two years and they say maybe, but the diary was busy. "But now I think England are ready to accept."