The former Portugal and Chelsea playmaker was in Mourinho's Porto team which won the tournament in 2004 and expects Chelsea to advance to the final after tomorrow's last four second leg with Atletico Madrid.
The Brazil-born midfielder, who played for Chelsea for two years from 2008, predicts Mourinho will face Real Madrid, the side he left last summer. "For him he can be in the final; it's the cup for him," said Deco.
"Maybe against his last team, Real Madrid, I think it would be very good for him. I think Chelsea will go through. He's a fantastic coach.
"When we won the Champions League with Porto, it was very good. He's still a friend. When a player wins it is amazing."
Meanwhile, Mourinho has denied a Football Association misconduct charge related to his post-match comments following the Barclays Premier League loss to Sunderland.
Mourinho could not hide his anger behind a sarcastic appraisal of the officials after his side conceded a penalty in the closing stages.