André Villas-Boas has admitted that Tottenham Hotspur must qualify for the Champions League in order to keep Gareth Bale from the clutches of predatory clubs, with Real Madrid preparing an offer for the player in the summer. The Tottenham manager also hopes that a massive price tag could serve as a deterrent for interested parties.

Bale is one of the hottest properties in European football and Real are monitoring his – and Tottenham's – situation closely. The Wales winger, who has scored 13 goals for Tottenham this season, plus four more for his country, is on record as stating his admiration for the Spanish champions.

Villas-Boas, though, believes that Tottenham would be set fair to retain Bale's services if they were to reach the Champions League. Bale got the taste for the competition in 2010-11 and, mindful that his opportunities might be limited at major international tournaments with Wales, he is determined to play regularly in Europe's leading club competition.

"Players who are performing at this level always get the attention," Villas-Boas said. "It doesn't mean that the club doesn't foresee a future with Gareth. It's intimately related to the objectives that we achieve for the season. Hopefully, we can do just that with the Champions League and continue to progress on what we are doing.

"It's difficult for us to have a player of this dimension playing so well, calling the attention of other teams but it's also difficult for other teams, with the economic situation as it is, to buy a player of this dimension. At the moment, we are very, very fortunate to have him.

"I think we can reach our objectives with him at this level and if we reach our objectives, we can hopefully continue to have Gareth in our club. He's a player we rate very, very highly and aren't willing to let go.

"The Champions League is where most of the clubs want to be, and where most of the players want to play. It's part of our objectives so hopefully achieving it means we can attract better players and continue to hold on to our best players."

Villas-Boas has played Bale as a central striker and he could use him there on Saturday lunchtime for the Premier League visit of Newcastle United, with Jermain Defoe injured and an element of doubt over Emmanuel Adebayor, who did not make it back from the Africa Cup of Nations in time for Thursday afternoon's training session.

Villas-Boas said that Adebayor was still in Africa on Thursday morning, despite his country, Togo, being eliminated from the tournament against Burkina Faso on Sunday. Adebayor is now expected to report for training at 3pm on Friday, with Villas-Boas saying that he would "not be 100%" for Newcastle.

Defoe damaged ankle ligaments in the Bale-inspired 1-0 win at West Bromwich Albion last Sunday and Villas-Boas reported that he would be out for "two to three weeks". That, though, would appear to be an optimistic prognosis. Defoe's foot remains in a protective boot and it cannot bear his weight.

People close to the England striker do not want him to rush his comeback, mindful that he did so when he previously suffered ankle ligament damage to do more harm than good. Defoe is more likely to be out for six weeks, possibly longer. It should be noted, however, that Defoe always wants to play.

Younès Kaboul, meanwhile, is set to return to training on Monday, after undergoing knee surgery last August but Villas-Boas remained cautious and he could not give a potential comeback date for the centre-half.

Bale's emergence as a more central force mirrors the development of Real's Cristiano Ronaldo and Villas-Boas drew the comparison between the two, while hoping that Bale did not follow his fellow Portuguese to the Bernabéu.

"Both of them are extremely technical players, extremely powerful and pacy," Villas-Boas said. "It is funny to see how, in some way, they compare. Gareth started at left-back and moved to a winger position ... now going to a more advanced role. And Ronaldo is also able to play that role up front. Ronaldo is now 28, he has achieved so much and he is an example to what Gareth wants to achieve in his career."