Newcastle United had risked its brand value by associating itself with Wonga, a marketing expert said.
Toon fan Dr Joanna Berry of Newcastle University Business School, who is based across the road from the stadium, said future sponsors might feel the club has been tarnished.
"If you were the Emirates, Virgin, British Airways or any of the global, creditable brands, would you want to follow Wonga?" she said.
"From a marketing perspective, the reputational risk is significant."
She said while it was a "clever" move to rename the stadium, it had never changed in the eyes of the fans.
More top news
The mother of missing RAF serviceman Corrie McKeague says she may take out an injunction to stop police filling in a landfill site.
Branden Grace exploited ideal conditions to record the first 62 in men's major championship history in the third round of the Open.
Relatives of those killed in the Hyde Park attack 35 years ago marched in central London to bring an accused bomber to justice.