Barcelona have reached a preliminary agreement with Sao Paulo to sign Brazilian defender Douglas.
Stefan Scepovic expects his departure from Sporting Gijon to be finalised soon but is not sure yet that he will be joining Celtic.
The former Chelsea boss is expected to leave Real Madrid this summer and has made no secret of his desire to return to England, saying this week it is where he feels loved.
Chelsea are favourites to re-sign their former boss, with Rafael Benitez's short-term contract up at the end of the season.
Tottenham boss Villas-Boas worked under his Portuguese countryman at Porto, Chelsea and Inter Milan and would welcome his former mentor back.
Villas-Boas said: "He obviously wants to come back to England, whether he has a club aligned or not, we never know.
"It's extremely unlikely when someone makes it that public that something is not set out already but he is a great addition to the Premier League. He has a wonderful history in this league and I think it will be spectacular to have him back."
Mourinho has won a significant haul of trophies at all his clubs but has found it most difficult at Madrid.
Defeat over two legs against Borussia Dortmund in the semi-finals means the Champions League will once again elude the Spaniards this season, and Villas-Boas acknowledged Mourinho probably has not lived up to the expectations Madrid had when he arrived.
The Spurs boss said: "When he left (England) he wasn't that well loved by a few of you guys (the media) and that was something we talked about.
"He was loved in all the clubs where he has won titles, in Real Madrid the same.
"There is maximum respect for what he has achieved, but for it to be at the level of Real Madrid's expectancy, we will never know. Probably not, but he certainly has won a league against a dream Barcelona team, which is a great achievement."
West Brom manager Steve Clarke and Swansea's Michael Laudrup would both welcome Mourinho's return to the Premier League.
Clarke was assistant manager to the 50-year-old at Chelsea, but he insisted: "I don't know if he's coming or not, that's the truth.
"I know he was happy here because he had a good job at a good club and we were successful. That's what he likes, he likes to win football matches wherever he is.
"If he comes back, it's great for the Premier League. If he does come back and we get the chance to play against him that would be great."
Laudrup, a former Real Madrid midfielder, added: "To have good managers in a top league is always good, and there will be a lot of nice press conferences for the media to look forward to.
"He is a good manager, you just need to look at his CV and what he has achieved with all his clubs, so for him to return to Chelsea would be good for the Premier League."