Jonny Bell broke down in training in Dublin on Monday

Ireland were hit by another blow to their World Cup chances with the withdrawal of centre Jonny Bell.

The Ulsterman was forced to pull out on Monday afternoon following further problems with a long-standing Achilles tendon injury.

Bell's provincial colleague Paddy Wallace has been called into the squad as his replacement.

The 29-year-old's career has been blighted with injury since he won the first of his 36 caps against Australia nine years ago.

''I am naturally bitterly disappointed,'' Bell told this website.

''I suppose in a way it's a great relief to know that I'm out, as I have been under considerable pressure to prove my fitness.

Now I will concentrate in getting myself back to full fitness and ready to play for Ulster Jonny Bell

''For the last two weeks in particular, I have been nursing my through things.

''It will be a long lonesome journey home to Belfast from Dublin thinking of what have been.

''Now I will just have to concentrate in getting myself back to full fitness and ready to play for Ulster again,'' said Bell who would have been taking part in his third World Cup campaign.

Ireland are now short in midfield with Rob Henderson and Geordan Murphy already missing the trip due to injury.

Shane Horgan has not played since injuring his thigh against Scotland back in February, while John Kelly, who can play midfield in an emergency, is still recovering from a rib cartilage injury.

The uncapped Wallace is a utility back for Ulster having played mostly at full-back, and is cover for David Humphreys when the fly-half is away on international duty.

Ireland are now left with Brian O'Driscoll and Kevin Maggs as the only two recognised centres in the 30-man party which leaves for Australia next Monday.

Revised squad