The club have confirmed that last season's top scorer Scott McDonald has suffered a groin tear, while Jan Vennegoor of Hesselink is rated only 50-50 for Sunday's Parkhead encounter after needing stitches in a deep leg gash.

McDonald missed Saturday's victory over Falkirk, which lifted champions Celtic above Rangers on goal difference at the top of the Clydesdale Bank Premier League.

It was hoped the problem, which he picked up on international duty with Australia last week, would clear up in time for this weekend's crunch clash, but the injury is worse than first thought.

Coach Neil Lennon said: "Scott has got a wee groin tear so he could be a doubt."

Depending on the severity of the tear, McDonald could even be a doubt for the start of Celtic's Champions League campaign next month.

Vennegoor of Hesselink lasted just 28 minutes of Saturday's 3-0 win before being stretchered off after a collision with Lee Bullen.

Lennon said: "Jan has got five stitches in an ankle injury so it could be 50-50 for the weekend. We will just have to see how he is."

McDonald and Vennegoor of Hesselink combined to net 51 goals for Celtic last term and their loss would be a major blow to the club's hopes of gaining the early-season initiative over Rangers.

Georgios Samaras and new signing Shaun Maloney proved to be an effective partnership for almost an hour against Falkirk, but there now appear to be few alternative options for manager Gordon Strachan in any case.

There was better news on Gary Caldwell's thigh injury. The defender, who picked up the problem in Celtic's 1-1 draw at Dundee United 11 days ago, is on track to return against Rangers.

Lennon said: "Gary had a thigh problem. But with the rest over the weekend, he should be fine." Meanwhile, Shunsuke Nakamura has refused to divulge who he wants to face in the group stages of the Champions League – but he is clear on the teams he wants to avoid.

The Japan international is eagerly anticipating tomorrow's draw, when the Scottish champions will discover this season's opponents.

Nakamura has already faced AC Milan, Benfica, Manchester United, FC Copenhagen, Shakhtar Donetsk and Barcelona on the European stage.

"We seem to play Milan and Benfica every year," he said. "To be honest, I don't really want to say which teams I want to draw. In the past, I said I wanted to play Milan and it happened.

"I also said I'd like to draw Barcelona and that also happened. If I say this time, maybe it won't happen!

"What I can say is that I don't think we want to play Benfica or Milan again. All I want to do is play against some of the best clubs in the tournament."

Lyon, Arsenal, Liverpool, Juventus, and Real Madrid are all potential opponents this time around.

"I watch those teams a lot, especially the Premier League sides, so maybe that would be good," Nakamura told the Celtic View .

"Let's wait and see what happens on Thursday."