Fears are growing surrounding the availability of Marcus Horan for the upcoming autumn internationals after the IRFU confirmed the Munster prop was undergoing “a series of tests and investigations”.

Horan has not played since October 17 when the he was forced off early in Munster's Heineken Cup win over Treviso complaining of dizziness.

The Grand Slam winner was not in camp with the rest of the squad yesterday, with the 32-year-old's availability for the three-game series due to be known by the end of the week when the relevant tests are expected to be completed.

Declan Kidney seems to be well covered in that area having named seven props in his initial 39-man squad, which will be reduced to 30 on Friday.

Tom Court and Leinster starlet Cian Healy are most likely to fill the void should Horan be unavailable.

Gordon D'Arcy, Tommy Bowe, Leo Cullen and David Wallace all sat out yesterday's session in the University of Limerick while Rob Kearney (hamstring), Brian |O'Driscoll, Jerry Flannery and Tony Buckley (all calf) took a light part in training as they continue to recover from their respective injuries.

Meanwhile, Jonny Wilkinson looks set to win his first international cap since March 2008 when England face Australia at Twickenham on Saturday.

And the Toulon out-half could start in the same team as hooker Steve Thompson for the first time since England's historic 2003 World Cup final win over the Wallabies.

Northampton's Dylan Hartley has also been included in the 22-man squad named by Martin Johnson after he passed a late fitness test, but Gloucester centre Mike Tindall misses out with a hamstring injury.

In all, Johnson has a staggering 27 players unavailable for selection because of injury.

Johnson's squad could produce the most inexperienced England team in recent times, with the starting XV to tackle the Wallabies likely to contain 11 players with 13 caps or less, six of whom count their international appearances in single figures.

Even with veteran campaigners Wilkinson, Lewis Moody and Steve Borthwick in the team, the average number of caps per man is a paltry 19.

Connacht coach Michael Bradley has set his sights on qualifying for the Heineken Cup in his final season with the province after announcing that he will step down from his role as director of rugby at the Sportsground at the end of the current season.

Bradley said the announcement was timed so as to allow Connacht find the best possible replacement.

“I am grateful for the support I have received from CEO Gerry Kelly, the coaches, office staff and particular the players since arriving here in 2003,” said Bradley in a statement yesterday.

“Whilst not achieving the consistency in performance that all directors of rugby crave, Connacht has had some fantastic nights especially in the Sportsground and these are great memories.

“I would like pay a special thanks to the Connacht supporters.

“They are an inspiration to our team and long may that continue.”