Gordon Strachan has confirmed his interest in signing Thomas Gravesen and Serbian hitman Daniel Ljuboja.
Talk of Celtic being interested in Real Madrid star Gravesen had not been taken seriously considering the club's hard-line tactics over transfer fees and players wages.
The Spanish giants would demand £2 million for the player but the fact Strachan and chief executive Peter Lawwell are still interested suggests they are not scared by the price.
The stumbling block however would be the Denmark international's wages and the Hoops boss has warned him he would have to take a cut to fit into his pay structure.
Strachan said: 'We are actively trying to sign players and Peter (Lawwell) has been in Europe this week, trying his best to bring in players.
'It's not for me, the fans or Peter but it's for the players because they need more players beside them.
'We have lost some huge personalities over the past six months and we need to get good personalities and players to help these guys, who are working extremely hard.
'There would have to be some homework done on those (Gravesen) wages and we would like to try to keep him in the structure we have just now.
'It's unfair to speak about anybody that's not here and on something that might possibly happen but we are looking to bring in quality players within our budget.'
Celtic have also been strongly linked with a move for VfB Stuttgart striker Ljuboja but the German club are demanding a fee in the region of £1.4million.
Celtic also remain in talks with Wolves over the possible capture of full-back Lee Naylor.
Strachan added: 'That's another one that (Wolves chief executive) Jez Moxey was talking about and I'd be lying to say I'm not interested.
'We will see what we can do but again it's a money issue.'
Meanwhile, Strachan has revealed his predecessor Martin O'Neill has approached him over possible capture of Stilian Petrov.
Speculation has been rife that the new Aston Villa boss was preparing to raid his former club for the Bulgarian international midfielder.
The want-away star has expressed a desire to quit the club despite signing a new contract last winter, while Celtic insist he is going nowhere.
But O'Neill has been given very little encouragement by the man who replaced him at the helm in the East End of Glasgow.
Strachan said: 'I spoke to Martin this week but the conversation is finished and Stan is still our player.'
