Real Madrid's newly-recruited midfielder Arda Guler has undergone successful knee surgery, the Spanish club said Monday.

Madrid said Guler "underwent an arthroscopy of the right knee today (and will) begin physiotheraphy in the coming days".

Guler signed a six-year contract with Madrid last month but will start the season on the sidelines.

No time frame was given for the 18-year-old's debut but reports estimate it could be up to two months.

The Turkish prodigy was signed from Fenerbahce under the noses of arch-rivals Barcelona for a reported 20 million euros ($21.7 million).

A left-footed playmaker, the teenager in June became the youngest player to score for Turkey.

Madrid's Brazilian defender Eder Militao and Belgian goalkeeper Thibaut Courtois are also set for surgery on ruptured cruciate knee ligaments.