Harry Redknapp hopes Luka Modric will follow the likes of Gareth Bale and Rafael Van der Vaart and share the belief that he can achieve domestic and European glory at Spurs.
The Croatian international has been linked with a move away from the club since the transfer window opened, but the Spurs boss has urged his owners to be as ambitious as the top Barclays Premier League clubs, such as Chelsea, where Modric has set his sights.
Redknapp said: "He has a fantastic contract but maybe he sees the chance to win the Premier League and play in the UEFA Champions League.
"He sees it as a big opportunity for him but we want to keep him as well, he is a top player for us. We have to show the ambition to keep these players, your Lukas, your Rafas, your Gareth Bales.
"If Modric goes, he weakens us and if you start to letting your best players go who knows where we will finish up."
The 25-year-old playmaker has filed a written request to leave White Hart Lane, and Chelsea have put more pressure on Redknapp with an improved £27 million bid.
Manchester United are also waiting in the wings for Modric, but with Alex Ferguson unwilling to enter a bidding war for the restless player, Chelsea are odds on favourites to bag their primary target.
But the 64-year-old boss is standing firm. In response to Modric's written request, Redknapp said: "We know he wants to leave, whether he writes it down on a piece of paper doesn't really make any difference to our stance. He's a great player and we don't want to lose him."
Redknapp's latest comments on the long-running saga look set to galvanise his squad after a disappointing preseason defeat to the Kaiser Chiefs. Modric sat out of the 1-0 loss due to an ankle problem, but should be ready for Tuesday's face off against the Orlando Pirates.