Spain's King Juan Carlos will undergo surgery next week on his left Achilles tendon, sources within the royal household told Efe on Thursday.

The monarch will be operated upon by the same medical team at Madrid's San Jose hospital that performed surgery on June 3 on his right knee, which had been bothering Juan Carlos for several years due to a 1991 skiing injury.

According to the sources, the king will not need to be hospitalized before or after the surgery, but he will have to undergo post-operative rehabilitation and suspend his official agenda for a couple of weeks.

Although his recovery from the knee operation was proceeding well, Juan Carlos evidently strained his left leg, producing tendinitis that has been becoming more aggravated.

At the beginning of August, the king began using an orthopedic boot to immobilize his left foot after suffering the first symptoms of the tendinitis.

Doctors believe that this latest health issue could stem from the extra compensatory effort the monarch was making with his left leg after the surgery on his right knee.