Tottenham Hotspur legend Ossie Ardiles warned the club must bring more top quality players to White Hart Lane if Spurs are to push for a top four place.
Spurs have improved significantly under Harry Redknapp and could finish this season with a place in next season's new Europa League, which replaces the UEFA Cup.
But Ardiles said: 'I have a feeling that Harry is not happy with what he has. To break into the top four Spurs are going to need a lot more. I think Harry will move quite strongly in the transfer market this summer.
'He has to build the squad so he needs quality players. To bring in another player similar to what he's got already is only OK for a mid-table team.
'If you want to fight for a place in the top four you're talking about bringing in real quality players. It's not easy because players of this quality want to be involved in the Champions League. I think he will probably be looking for another front man and a creative midfielder.
'Robbie Keane and Jermain Defoe will be number one for a start next season. Now it is up to Harry to see if he can get someone of the same quality or better.'
Ardiles predicted a bright future for Croatia international Luka Modric.
He said: 'Modric needs a bit more time. At the beginning he looked lost. Now he is looking better and better. He is a very good signing and the best is still to come from him, certainly.
'He just needs time to adjust fully to English football. It's more physical and much quicker, but he will do well.'