But yesterday he was given the all-clear and is likely to be named in the Scotland team to face the defending champions, South Africa, at Murrayfield on Sunday, bringing a glittering career in rugby league and union full circle.
Tait, now 35, made his Scotland debut in the first World Cup in 1987 and his appearance in the fourth global tournament puts him in a unique position. "Some players have two or three highlights in their careers," said a relieved Tait yesterday, "and that is just in one sport. I have been fortunate to have changed sports a couple of times and enjoy success in each."
Tait, who has scored an impressive 16 tries in his 24 international appearances for Scotland as well as scoring one for the Lions in 1995, also made 16 appearances for the Great Britain rugby league team in his nine years in the 13-man code.
Since becoming a part of the union again Tait has enjoyed an Indian summer to his career. Last season he played at outside centre and helped Scotland win the Five Nations' Championship.
Now he is looking forward to Scotland's World Cup opener against the Springboks. "It is a massive game for us. We have played South Africa twice since I came back and we have been turned over on both occasions. And if we don't win on Sunday then we are looking at having to face New Zealand in the knock-out stages and that will be tough.
"Realistically winning the World Cup is probably beyond us, but if we get past the quarter finals we will have done better than anyone has a right to expect."
And World Cup expectations are high across the water in Dublin, only this time on the financial front. The World Cup is expected to inject more than pounds 40m into the Irish economy. That was the confident prediction of the Irish Rugby Football Union.
According to a survey commissioned by the IRFU the Republic can look forward to an influx of some 40,000 rugby fans during the next three weeks.
The survey conducted by the Graduate School of Business Marketing Development at University College in Dublin estimates that international rugby played in Ireland during the last two years had contributed a similar total to the nation's economy and the IRFU chief executive, Philip Browne, expects the five matches being staged in Dublin, Limerick and Belfast to bring in an improvement on that.
The IRFU has spent more than pounds 4m upgrading the three grounds, installing floodlights, terracing, medical facilities, a new playing surface and toilets at Limerick and around a quarter of a million pounds has been ploughed into Lansdowne Road to provide a control tower incorporating media studios and a police control centre.
Back in the real rugby world where clubs are having to make do without their World Cup stars, Leicester have addressed their crisis at lock by signing the Australian international second row John Welborn.
The 29-year-old who just missed out on a place in the Wallabies' World Cup squad has six caps, including two appearances in the Tri-Nations series which has just ended and is likely to make his Tigers' debut at Gloucester onFriday. Allied Dunbar Premiership.Reuse content