England fly-half Charlie Hodgson says he does not think he will be back to fitness in time for the two-Test trip to South Africa at the end of May.
Hodgson is a month away from regaining full fitness
Hodgson suffered a serious knee injury in the autumn and expects to be back for the World Cup in September.
But Hodgson says he thinks the trip to South Africa will come too early.
"I want to make sure the knee is right - I think the South Africa tour is just slightly too soon," he said in a Rugby Football Union interview.
Hodgson believes he is about a month away from full fitness.
"From my point of view I've ruled the tour out - it's a lot to expect to play international games anyway, particularly when Brian Ashton says he picks people on form," said Hodgson.
"I haven't been playing and it would be wrong for him to pick me in the first place, but just from my point of view I don't want to rush things."
He's an amazing talent and one which will be missed by the game I'm sure
Hodgson on Jason Robinson
It is the second time in his career Hodgson has had to fight back from a cruciate ligament injury.
He missed England's victorious 2003 World Cup campaign after injuring his knee in the Six Nations.
Hodgson does not expect to miss the tournament this time, having started running a few weeks ago.
"There's no doubt I'll play again, it's just a matter of when," he said.
"All being well I have a month to go, but with the season finishing there isn't any rugby to be played - I guess it gives me a bit more time to recover.
"It's been a long, drawn out process. Obviously I'm getting towards the end now and there's light at the end of the tunnel."
During his absence the likes of Shane Geraghty and Toby Flood have emerged as serious rivals to Hodgson and the frequently injured Jonny Wilkinson for the England fly-half berth.
"Obviously it is frustrating seeing people playing well in your position but at the same time you've got to take your hat off to these guys," said Hodgson.
"They're only young guys, they've been given their first opportunities in an England shirt in the Six Nations really and they took them well."
While Hodgson has been on the sidelines, cross-code legend Jason Robinson, a Sale team-mate, has called time on his club career and Hodgson said he would be sorely missed.
"I think there's a legend that surrounds Jason Robinson whether he's playing league or he's playing union," said Hodgson.
"He's an amazing individual, he's had an amazing career and I can say I've been privileged to play with him."