Wilkinson has not played for England since the World Cup

"I am not sure yet whether I will be playing for Newcastle on Friday," he said in his column for The Times.

"I am trying to be sensible and make good decisions. The Lions are a big reason why we play the game and it is something I have got to fight for."

"I am looking forward to attacking the last few games of the season - it gives me even more of an incentive."

Wilkinson acknowledged the decision by Lions coach Sir Clive Woodward to leave him out of the original squad but give him scope to return at a later date should he regain full fitness.

"I have always had a lot of respect for him and the way he has handled this with me only increases that," said England's leading points scorer.

"He called me at the end of last week and asked how I was. Our conversation left me feeling comfortable with where I am but knowing I have a lot to prove."

I know there are not too many opportunities left Jonny Wilkinson

Since his last-gasp drop-goal in the World Cup final in Australia late in 2003, Wilkinson has been beset by a series of injury problems, and missed the last two Six Nations campaigns.

His most recent setback came last month against Harlequins, when he injured the same left knee that had kept him out for two months prior to that.

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"I have a few things to check out but I'm pretty happy with where I am fitness wise. We'll see how things are in a couple of days, I have worked hard on my rehab so hopefully now I can string a few games together.

"I know there are not too many opportunities left. If by any chance I can go on the tour, then fantastic.

"But I know that is only one step on the ladder. The party is full of fantastic individuals."