Goncalo Guedes
Guedes is not for sale according to the player's agent.Getty Images/Philipp Schmidli

Arsenal have been warned they must stump up £39.3m if they have any ambition of signing Benfica youngster Goncalo Guedes in the near future.

The 17 year old currently plays for the Benfica B team in the Segunda Liga, scoring three goals in 11 appearances while operating in a left wing role for the Portuguese giants' second string.

Among the clubs reportedly interested in Guedes, who has been compared to former France international Frank Ribery, include Arsenal and German champions Bayern Munich but despite several approaches for his services agent Paulo Rodrigues says he is not for sale.

"There are so many rumours about him but I, the player and the club want him to continue to play for Benfica," he told calciomercato. "His dream is to succeed with this shirt, I think he can become stronger than Cristiano Ronaldo.

"Guedes has a contract until 2019 and he costs €50m [£39.3]. Several clubs want the player, but no one is willing to meet the Benfica's demands and the club don't want to sell him."

The enormous valuation, which if matched would make Guedes the most expensive teenager in world football, is expected to put off any suitors of the Portugal Under 17 international,given that he is yet to play in the Benfica first team.

In the 2013/14 season Benfica ended a three year wait for the Portuguese League title and went on to sign 20 new players during the summer transfer window; an indication that Guedes' promotion into the first team might be some years away.

Arsenal manager Arsene Wenger has built a reputation on signing players in the infancy of their career and could be tempted to bet on Guedes becoming unsettled at Benfica, should he wait for a first team debut be prolonged.

However, any fee approaching his £39.3 valuation would almost certainly put off Arsenal who, despite recently ditching their much-criticised frugality, are unlikely to splash out such a ransom on a player without genuine experience.