Notts County have signed striker Adam Campbell after he impressed in a trial and Kyle De Silva.
Barcelona have insisted they are "not planning" a move for Juventus midfielder Paul Pogba this calendar year.
The Croatian has emerged as one of Hughes' top transfer targets for the summer, and he could move to the Britannia Stadium on a free transfer.
The 34-year-old has never hidden his desire to play in England, but admits current club Wolfsburg are also fighting hard to tie him down to a new deal.
Olic, though, has admitted that he did seek assurance from Hughes about their style of play.
"When I was talking with Hughes, I told him; 'My neck will hurt with your long balls, who on earth is going to catch them all'," he told Jutarnji List.
"He said to me: 'We don't play like that anymore, we want to play a European style of football'. That's okay for me but so far I have not yet decided.
"I would like to feel the atmosphere of Old Trafford and Anfield but at Wolfsburg they are insisting that I should stay. So that is still possible outcome."
Olic has been in impressive form for Wolfsburg since joining in 2012, scoring nine goals in his first season, which he has already managed to equal this term.