Wales' Stephen Jones feared his groin injury would wreck his World Cup hopes and might even ruin his entire season.
Jones is expected to be fit for Wales' World Cup opener
Jones said: "One of the muscles that attach to the pelvis had two tears, but the specialist decided I didn't need an operation so I was a relieved man.
"If I had required an operation, then I could have been out for a long, long time. It was probably the season gone."
The fly-half is now expected to be fit for the tournament opener next month but will miss all three warm-up games.
He gave Wales coach Gareth Jenkins a major injury scare last Friday when he was hurt during a pre-tournament practice session in Brittany.
After an initial scan showed a torn muscle, 29-year-old Jones then had an agonising wait until Wednesday to discover if the injury was serious enough to warrant surgery.
"It was a non-contact injury," explained Jones. "I passed the ball and felt something go - I knew immediately that something wasn't right.
"On Tuesday night, I just tried to keep myself busy and not give myself any down time, and fortunately, the appointment was early Wednesday morning.
"I had worked hard in pre-season and you are so excited about such a great tournament being on the horizon, and then all of a sudden you might not be able to take part.
"It was a case of trying to stay positive."
The partial tear to the tendon in his left groin has ruled Jones out of Wales' World Cup warm-up games against England (3 August), Argentina (18 August) and France eight days later.
Stephen is very much the lifeblood of this squad
Wales coach Gareth Jenkins
But he is expected to resume full training at the end of the month, and Wales are confident he will be fully fit for their tournament opener against Canada in Nantes on 9 September.
"I haven't done any work this week, but next week I will start building things up," he said.
"In three weeks' time, according to the specialist, I should be able to take part in everything.
"It would be brilliant if I was fit for the France game, but realistically, I am just delighted to have had this news that I will be available for the World Cup."
Jones has been in competition with James Hook for the number 10 jersey, Hook starring in the Six Nations win over England when he replaced the injured Scarlets man.
Coach Jenkins said he was delighted that Jones, who he named in October last year as the man to lead Wales at the World Cup, will be available for selection.
"Stephen is very much the lifeblood of this squad," he said.
"He is a key leader and vital to us not just because of his rugby experience and what he offers on the pitch, but because of the impact he makes on the squad throughout our time together."