World Cup 2006 qualifying: Brian Kerr's options on the left are ominously close to being narrowed dramatically ahead of tomorrow's key World Cup qualifying game in Basel with Damien Duff now faced with the prospect of joining John O'Shea on the sidelines.

The Chelsea winger picked up an injury after a kick on his calf muscle in Saturday's win over Cyprus but initial reports from within the Irish camp suggested he would be fit to play at the St Jakob Park after a couple of days' rest.

Prior to leaving for Basel yesterday, however, Kerr was clearly a good deal more concerned about the prospects of the young Dubliner having recovered sufficiently to feature in the game.

"I'm not the physio and I don't like tying things down in this sort of situation," said the Irish manager, "but it was a nasty kick he took and he wasn't able to train today. We'll see how he is tomorrow but at this stage I would say he's about 50-50 for the game even though he's very anxious to play."

Duff's absence would be a major blow to Kerr who insisted after Saturday's win that the Irish would go to Basel aiming to beat the Swiss. The strength of the assertion, combined with the quality of performance he had witnessed from Andy Reid, suggested he would retain the attacking formation he had just fielded against the Cypriots with wingers on both sides of midfield.

The injury situation has now complicated matters, however, with the loss of O'Shea creating a vacancy that has to be filled at left back. Steve Finnan is one of the prime candidates to replace the Manchester United player - Alan Maybury being the other - but he was also a strong contender to start in front of Steve Carr on the right side of midfield if Kerr opted to approach tomorrow's game a little more conservatively than he did the one at the weekend.

Given the circumstances, Kerr admitted yesterday that he has, "a bit of thinking to do over the next couple of days. There's a few things that we have to weigh up but I still have a couple of days before I have to name the team."

One major plus to come out of Saturday is the fact that neither of his strikers picked up any sort of injury and Kerr feels that, having played against Cyprus, the pair will be closer to 100 per cent fit for tomorrow evening's game.

"There's no doubt about it," he said. "Damien hasn't started a game at Chelsea so if he hadn't taken the knock he'd have been better off as well but Clinton (Morrison) has only had bits and pieces at Birmingham and Robbie (Keane) has had about a game and a half since coming back at Spurs so they'll both feel the benefit of the run out they had at the weekend.

Asked about the other results in the first round of qualifying games Kerr expressed surprise at the scale of Switzerland's victory over the Faroe Islands but said that the result made little difference to his assessment of Ireland's game in Basel.

"We all would have expected them to win," he said, "but the number of goals surprised a little all right. In the last qualifying campaign I think the worst defeat they suffered was 3-1 against Germany so it's strange to see them conceding this many goals, although the time I saw them, against Poland, they did let in six as well.

"The fact is, though, that the Swiss beat us fair and square last time around, Alexandre Frei, who is suspended, is the only one they're without who would have played while we're without four or five and they're at home so I don't think there's any question but that they'll start Wednesday's game as favourites."

Despite having missed Manchester United's last couple of games, Kerr said that he expects Roy Keane to be fit enough to start tomorrow, something that is likely to cost Graham Kavanagh his place in the team.

The 30-year-old Dubliner was philosophical about developments within the squad since Saturday but insisted as well that Keane's likely inclusion needn't necessarily mean his having to drop down to the bench.

"First and foremost we're here for the squad, like everyone else here I'm a fan as well as a player and we want to get the best result for the country," he said. "But I was disappointed the last time in Switzerland when I didn't play. If we come back after this game with a win I'll be happy but of course if I haven't played I'll be a bit disappointed about that too.

"From my point of view I believe I can play with Roy, our styles aren't too similar. In fairness, though, I suppose Roy could play with anyone he's that good, he's proven that countless times at European level with Manchester United and at international level but I think I've done all right when I've been involved. Saturday was a good team performance, very professional and I'm proud to have been a part of it so yeah, I'd be delighted to play alongside him if given the opportunity."

Such a partnership does seem unlikely, however, although if Duff ends up missing the game and Kerr opts to field Finnan, despite his relative lack of experience in the position, at left back then Kavanagh, who watched last year's game in Basel from the stands when many felt he should have at the very least have been on the bench, may yet get his chance to play alongside Keane in the centre.