Cardiff will allow long-serving Kevin McNaughton to leave this summer along with Danny Gabbidon and Nicky Maynard.
Highly-rated Atletico Madrid midfielder Saul Niguez has signed a new five-year contract.
Bournemouth have signed Aberdeen winger Ryan Fraser for an undisclosed fee.
The 18-year-old Scot has signed a three-and-a-half-year deal at the Goldsands Stadium.
Having come through the Dons' youth ranks, Fraser made his debut in 2010 but only became a first-team regular in the last few months.
"He is a talented lad," Cherries boss Eddie Howe told the club's official website. "He's only 18 but he's very, very highly regarded in the world of football, especially up north and Aberdeen were desperate not to lose him.
"He came to our attention a while back and he's someone that we have tracked for a long period of time. We had a lot of competition for his signature but the fact we were able to sign him is a real positive for his football club.
"There will be a period of adjustment for a young lad to come all this way
but we will look after him and do all the work we need to do with him to try and improve his game. If we can and the move goes as well as we hope it can, I think we have got a top player on our hands."
Fraser has made 18 appearances so far this season and made his Scotland Under-19 bow against Germany back in August.
Aberdeen manager Craig Brown said: "I'm disappointed that we're losing him but he seemed anxious to go and he was advised his future was elsewhere.
"We had resigned ourselves to losing him."
Brown had hoped there might have been a rethink after Fraser returned from a six-week injury absence in the December 29 win at Dundee
"He got a good response from the fans when I put him on at Dundee," Brown said. "I thought that maybe because the fans were so good to him that he might have reconsidered the decision but he didn't.
"We are used to losing players and you just have to shrug your shoulders.
"I think he will flourish. I will not be churlish and wish him anything other than the very best.
"I'm sure he will flourish, unfortunately it won't be in the red jersey we have got here. It's a club on the up and up. They are in the third tier of English football but it's a good level of football and they are an ambitious club."
Dons chief executive Duncan Fraser explained the club's decision on their official website.
He said: "Right from the start we indicated that we had no desire to see Ryan move and that if it were to happen, a bid well above the training compensation fee due in the summer and with add ons would need to be forthcoming."
He added: "It is worth pointing out that eight young players have signed contract extensions over the last few weeks and we remain absolutely committed to youth development as the way ahead for this club, understanding that along the way some players will choose to move on at the end of their contracts."