Club president Godinho Lopes told reporters he was surprised by Tuesday's statement from UEFA which said Sporting were among 23 clubs to have prize money withheld because of overdue payments to other teams, their own employees or social and tax authorities.
"I can't say I am pleased with the ruckus around this issue," said Lopes. "I was sad to see Sporting's name mentioned, there was a communication error."
Jose Guedes, the club's vice-president in charge of financial affairs, said they did not understand why UEFA's announcement came before the October 14 deadline for teams to comply with the new fair play rules.
Sporting added there was a minor issue with payments to other clubs but that there were no salary delays and that taxes and social security payments were in order.
"The case is related to payments to football clubs and the sums are really not too big," Guedes said.
The club, who are looking for investors to improve their financial situation, posted a loss of 46 million euros from July 2011 to June 2012 - a four per cent rise driven mainly by player purchases.
They last qualified for the Champions League four years ago and this season have been drawn in Europa League Group G alongside Switzerland's Basel, Racing Genk of Belgium and Hungary's Videoton.