That was the warning to senior officials at the Glasgow giants yesterday as they edged closer to renaming the world-famous Govan ground.
Light Blues chief executive Charles Green got the go-ahead from supporters last week and is expected to make an announcement soon.
Carsten Cramer oversaw the sponsorship of the first stadium in Germany – the Volksparkstadion where Hamburger SV play – back in 2001.
Cramer is now marketing director at Bundesliga champions Borussia Dortmund and manages their bumper €21million deal with Signal Iduna.
He feels selling the naming rights to Ibrox will only succeed if both the club and the sponsor agree to a lengthy arrangement.
Green had initially suggested that one-year deals will be agreed with stadium sponsors – but it now looks likely at least a five-year deal will be struck.
Sports Direct, who already have a financial tie-up with Rangers to sell club merchandise, are strong favourites to win the contract.
Cramer said: "If the stadium name is changed every few years then people will lose their acceptance. Hamburg have had three or four different sponsors in a row. That doesn't help to convince people to the merit of the arrangement.
"A long-term commitment is needed. In our minds at Borussia Dortmund, this is very important for the success of the deal with Signal Iduna.
"From the beginning of our negotiations with Signal Iduna, we made it clear they would stay for more than five years.
"The contract started in 2006 and ran until 2021. It is for a minimum of 15 years."
"If it was the Sports Direct at Ibrox one year and then, say, Heineken at Ibrox the next year it would not work. You can't do that," he added.