Harry Kane could become "disgruntled" and look to leave Tottenham unless the club begins to challenge for silverware, according to former Spurs striker Gary Lineker.
England forward Kane has hit 128 goals in 194 appearances for Spurs since making his debut in 2011, winning the Premier League golden boot in each of the last two seasons.
The 24-year-old has been in sensational form this campaign, averaging a goal a game in his 29 outings in all competitions as well as overtaking Teddy Sheringham to become the club's record Premier League goalscorer.
Sky Bet have priced up Real Madrid at 12/1 to sign Kane during the current transfer window.
The striker is odds-on at 1/50 to stay with Spurs for at least the rest of this season.
Despite Kane's personal successes, Spurs have not lifted a trophy since their League Cup triumph a decade ago and Lineker, who won the FA Cup while at White Hart Lane between 1989 and 1992, feels the club must match the ambitions of their best players to keep hold of them.
Lineker, who was promoting the It's a Penalty campaign which aims to prevent the abuse, exploitation and trafficking of children from across the world, told Press Association Sport: "I think Tottenham have to decide what they are.
"I think if they want to keep the likes of Kane and (Dele) Alli, their star players, they'll have to pay the going rate, or get close to it and they'll also have to bring players in and challenge for titles because the great players want to win things, they want to be at places where they can do that.
"I suspect Harry Kane, he'd love that to happen, I think that would be his preference.
"But at the same time, if Tottenham don't show the same ambition perhaps as one or two of the players, then they'll get a little bit disgruntled and they might seek different areas and different places to play, so it's a bit of a watershed moment for Tottenham."
Lineker's spell with Spurs came following a three-year stay with Spanish giants Barcelona.
The England legend moved to the Nou Camp from Everton in 1986 and knows from experience how difficult it can be to resist interest from one of Europe's top clubs.
Asked whether he thought Kane would be tempted to make a similar move, Lineker replied: "When those big boys come calling, it's quite difficult.
"It depends on your personality and what you want out of life and where you want to go, so we've all got different circumstances so we'll have to wait and see."