The France international was forced off during Madrid's 2-0 La Liga win over Espanyol on 3 May after appearing to hurt his right leg. Medical tests later revealed a tendon injury in the rectus femoris muscle.
Initial reports in Spain suggested the problem could keep the former Olympique Lyonnais full-back out for close to a year, raising fears over his long-term future and availability for next season.
However, Real Madrid delivered a more encouraging update following the operation.
In an official statement, the club said: "Our player Ferland Mendy underwent successful surgery today, under the supervision of the Real Madrid Medical Services, for an injury to the rectus femoris muscle of his right leg."
The operation appears to have gone smoothly, and the recovery period is now expected to be significantly shorter than first feared.
According to reports from Madrid insider Jorge C Picon, Mendy is likely to spend around five months on the sidelines. That timeline would give the defender a chance to return before the end of the calendar year if his rehabilitation progresses well.
The injury is another frustrating setback for Mendy, who has struggled with fitness problems in recent seasons despite remaining an important part of Madrid's defensive system when available.
Former Manchester United defender Jaap Stam has backed the idea of a swap deal involving Marcus Rashford and Rafael Leao as uncertainty continues to surround Rashford's long-term future.
Real Madrid coach Alvaro Arbeloa admitted his side must focus on the collective rather than individuals after rivals Barcelona sealed the LaLiga title with a 2-0 El Clasico victory at Camp Nou on Sunday.
Barcelona sealed back-to-back La Liga titles with a dominant 2-0 victory over Real Madrid at Camp Nou on Sunday on what was an extra emotional day for manager Hansi Flick.
Barcelona head coach Hansi Flick has highlighted the "special atmosphere" inside his squad as his side move within touching distance of the La Liga title ahead of Sunday's Clasico against Real Madrid at Spotify Camp Nou.
