Imran Ahmad, whose employment with the Glasgow club was terminated last year, maintains that he is due the bonus money in an action being contested by Rangers.
Ahead of a four-day hearing of evidence and legal submissions due to begin on April 1 at the Court of Session in Edinburgh his lawyers sought to freeze a sum of cash.
But Lord Tyre rejected the motion for arrestment following an opposed hearing.
The judge said he was satisfied that a case at first sight had been made out based on a contractual term, a letter from former chief executive Charles Green and an acknowledgement that some work had been done.
But he added: "I readily acknowledge there is a great deal to argue about at the proof."
The judge said that he was not satisfied that there was a real and substantial risk that enforcement of any court order if Ahmad succeeded in his claim would be prejudiced by insolvency.
Lord Tyre said that the finances of a company such as Rangers were cyclical and there is a dip at this time.
But he found no clear evidence in what had been placed before him that there has been a deterioration in the position since June beyond any cyclical effect.
The judge said he would not regard it as reasonable in all the circumstances to grant a warrant at a time when Rangers has received a pounds 1.5 million working capital injection to take a third of that out of circulation.
More to follow.