The 24-year-old flew back to Cardiff on Monday night, having been unveiled to the Real Madrid fans at the Bernabeu at lunchtime following his 100million Euro move from Tottenham.
Bale made it clear at his unveiling he was keen to join up with Wales in order to regain fitness ahead of his Real debut, and Coleman is delighted to have him available.
But with the winger not having played since July, Coleman will not take any risks with his fitness.
Coleman told a packed press conference in Cardiff: "If he is not ready we will not risk him, regardless of whether it is a world record fee.
"We are aware a lot of people will want to see him play in the home game against Serbia.
"But he has no chance of playing 90 minutes on Friday or on Tuesday."