Spurs held talks with Sporting Lisbon over signing the Portugal international this past summer.
But Mourinho has suggested Tottenham can't afford to sign Fernandes next month.
"I would definitely say no because Bruno is a player of a level and value that is not for us," he said.
"We are not a club that is going to make big transfers in the market, nor is it going towards players who are already developed or at a certain level of expectation, also economically.
"We are a different club at this level."