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In his BBC column, the Wales centre revealed that without at least six to eight weeks' rest he could require reconstructive surgery on the joint.

"I'm pretty devastated to be ruled out, I'd earmarked the tour to really make a claim," Harris told BBC Sport.

"I've got severe bruising in the shin and quad bones, I've also got a tear in the posterior cruciate ligament."

Harris is just the latest player to be ruled out of the tour, which is the first real opportunity for new coach Mike Ruddock to shape his team.

Scarlets duo told to rest

Scarlets forwards Robin McBryde and Dafydd Jones are almost certainly out with shoulder injuries.

Lock forward Robert Sidoli and full-back Kevin Morgan, both at the Celtic Warriors, are also likely to miss out.

Wales could also be left light at half-back, with fly-half Stephen Jones and scrum-halves Gareth Cooper and Ryan Powell struggling.

Powell and Harris are not the only casualties at the Cardiff Blues, with flanker Martyn Williams and centre Jamie Robinson suffering serious knocks themselves.

Ruddock was meant to name his tour squad on Wednesday, but that announcement has been put back until 17 May to check on injuries after the final round of Celtic League matches this weekend.

"It's been an extremely long year with the World Cup, we've been playing international rugby since July last year," Harris added.

"There's only so much a body can take at that level and over the next two or three weeks you'll see plenty of players dropping out of tours - not just for Wales but for every country that's going on a tour."

Wales play back-to-back Tests against Argentina on 12 and 19 June in Tucuman and Buenos Aires, finishing with a showdown against South Africa in Pretoria on 26 June.