Former Celtic star John Hartson revealed that he immediately rebuffed Sir David Murray when the Rangers owner tried to entice him to Ibrox 15 months ago.
The Welshman failed a medical at Rangers when Dick Advocaat was manager and he subsequently signed for Celtic where he became a fans' favourite under Martin O'Neill.
But during Paul Le Guen's ill-fated tenure at Ibrox, Murray tried to persuade Hartson to leave West Brom for what would have been a sensational return to Glasgow.
However, the former Wales international claims Murray's phone call was a waste of time.
"There was no way that I could ever pull on a Rangers shirt after all that I achieved in five years at Celtic," Hartson told the Scottish Sun.
"Mr Murray tried to convince me it would work but it was a no-brainer as far as I was concerned.
"It's a call that I will never forget but one I had to say no to.
"There are two clubs in the world that I could never contemplate playing for now - Cardiff City and Rangers.
"Mr Murray could have offered to pay me a £1million per week and I would still have said no.
"Honestly, I'm being serious when I say that.
"Put it this way, I didn't even ask him for time to think about it.
"That would have been a waste of his time and I didn't want to do that.
"In the end, he accepted what I had to say and we wished each other all the best.
"I didn't hear from him again and that suited me fine."