The former captain, who injured his knee in Scotlands 48-6 victory over Romania at Murrayfield in November, will fly out to Vermont on Saturday with Sale Sharks team-mate Charlie Hodgson to see knee specialist Bill Knowles.

The pair will spend four weeks in the United States working with Knowles, who predominantly deals with injured skiers, as part of an initiative funded jointly by the Scottish RU, the RFU and Sale.

Already ruled out of the rest of the Premiership campaign, White is hoping to be back playing by May and told a press conference in Cheshire on Thursday that the World Cup is definitely in his thoughts.

Its a big focus for me to push on with my training, said White, who hopes to make his comeback with Scotland A in the Churchill Cup this summer. I want to get back for Scotland desperately.

My short-term goal is to try to have a bit of fun in the rehab and make that as enjoyable as possible and then look at longer term goal which is the World Cup.

White admits he has been frustrated watching Scotlands inconsistent RBS 6 Nations campaign but is anxious not to raise expectations in advance of his return.

Id obviously love to get back playing for Scotland but there is a difference between being fit and actually playing well, he said.

Im realistic. Scotland have got very good back rows. Just because Im fit, it doesnt mean that Im going to be playing international rugby and performing like an international player. Thats two different things.

I want to get back and play for Scotland again but Ive got to get fit.

White is in philosophical mood as he copes with the worst injury of his career and is determined not to come back too soon.

Its my first serious injury, so I feel very lucky that I played eight or nine years at the top level without missing a big chunk of rugby, he said.

I was quite realistic that it was going to come along at some point. There is never a good time to have it.

The worst point for me is seeing the muscle wastage and the best point is seeing it come back.

Its trying to let Mother Nature take its course. Im working as hard as I can and Ill be fit when my body tells me that Im fit.