Rugby: If it wasn't for his bad luck Rob Henderson wouldn't have had any luck at all these past couple of seasons. Dogged by injuries in that time, the Munster and Ireland centre was keen to revive his international career in the forthcoming tour of Australia, Tonga and Samoa but yesterday sustained a torn calf muscle, which has sidelined him for three weeks.

His Munster midfield partner Mike Mullins has been called up in his stead.

Ireland manager Brian O'Brien last night confirmed that Henderson sustained the injury in the warm-up to yesterday morning's training session in Wanderers' Merrion Road grounds, and scans later revealed the full extent of the injury.

Henderson missed much of last season with damage to his knee from the Lions tour and was sidelined for three months this season by a torn bicep, which he sustained in Munster's defeat to Gloucester in October.

Despite supplementing his work with Munster and Ireland with his own personalised training regime, even when returning to fitness Henderson was troubled by a calf strain which ruled him out of the Ireland A side's win over England, and was no doubt a harbinger of the full-scale tear he suffered yesterday. He will be sidelined for three to four weeks.

"He's gone home already and is desperately disappointed," said O'Brien. "He's been very unlucky these last two seasons. Mike Mullins has been called in so one door closes and another opens, but it is very unfortunate for Hendo."

Gary Longwell is the only other doubt among the 41-man squad, which is due to depart for Australia in two groups, tomorrow and Friday. The Ulster lock has contracted a virus which is expected to clear up well in advance of the Test against Australia in Perth next Saturday week, but the proximity of the long-haul journey through Singapore, and the nature of his problem, makes his condition a cause of concern for the Irish management.

"Gary has a temperature and is being kept in isolation so to speak," admitted O'Brien. "He is being monitored and obviously hasn't trained with the lads for the last couple of days. It should clear up in time but it's a bit like asking 'how long is a piece of string?' "

Peter Stringer had recently been bothered by a sore knee, which O'Brien admitted was "slow to respond initially", but he resumed running yesterday at Merrion Road, where the squad will have their final run-out together before they begin leaving tomorrow.

The first group will involve the dozen or so players who have been earmarked for a return journey after the Perth Test, with the remainder travelling on to Tonga and Samoa for Tests on June 14th and 20th.