Sergen Yalcin, the skilful Fenerbahce midfield player, yesterday went some way towards allaying doubts about his fitness for Saturday's big game when he joined his Turkish team-mates in a training session at Portmarnock.

Yalcin has not played in either of his club's last two games but a Turkish official explained that this was because of the need to rest him for the two European Championship meetings with Ireland.

Together with Hakan Sukur and Aris Erdem, Yalcin has been identified by Mick McCarthy as one of the bigger threats in the Turkish team. And McCarthy is supported in that view by the Leicester City and Northern Ireland player Neil Lennon.

Lennon, who was in the Northern Ireland team which twice lost to the Turks in the qualifying series, says: "Tugay Kerimoglu may be their captain and principal ball winner in midfield but it's Sergen who produces the passes which split defences.

"Somebody has to sit on him and I think that's a job for Roy Keane. If Keane stops their playmaker, the Turks will be a lot less composed. It's a huge bonus for the Republic to have Keane back - maybe even the tie winner."

Although Northern Ireland were comprehensively beaten in both their encounters with the Turks, Lennon believes that the Republic will do a lot better. "For one thing, Mick McCarthy's team will not give away the kind of daft goals which we conceded.

"They are much more experienced than us at this level of competition. They'll know precisely what is required and despite the loss of some good players, will fancy their chances of going and doing it.

"Overall, I believe the Turkish players will be very nervous about coming to Dublin. They know the Republic were unlucky not to have qualified automatically for the finals. And since they get Premiership games on their local television, they'll be aware of the huge physical presence of Niall Quinn.

"I have played against Quinn recently and he was outstanding. The big man has far better feet than he is given credit for. And the Turks are also unlikely to be unaware of the fact Robbie Keane is flying for Coventry."

Lennon adds: "Turkey are very much a flair team - they're not used to having to grind out results. It will be fascinating to see how they handle a partisan crowd and an aggressive home team in the first-leg game."