Taarabt's career at QPR has been mixed and the mercurial forward spent all of last season away from Loftus Road, first joining Fulham on loan for the first half of the 2013-14 campaign before moving to Milan in January.
The Serie A giants were linked with a permanent deal for the Morocco international, but were unwilling to meet Taarabt's asking price that was reported to be £6 million.
With the transfer window now shut, Taarabt will remain with the London side and Fernandes has backed him to follow in the footsteps of midfielder Barton.
"Like many people who wrote off Joey - and he was key for us last season - Adel is going to be something special," he told the Evening Standard.
"People have forgotten about him a little bit but he can do extraordinary things. At AC Milan last season he was quite special.
"I think Adel will be a surprise for many this season. He's focused and wants to stay at QPR. He can turn games around in a few minutes, so it's important to have him."
