Dr. Xavier Mir, one of the doctors tasked with fixing reigning MotoGP champion Marc Marquez's frequent left shoulder dislocations, has said Tuesday's surgery was "more complicated than expected" due to the level of joint damage.

Marca.com also quotes Mir as saying, "I almost do not understand how he was able to win the world title like that… it gives him more merit."

Explaining the surgery further, Mir revealed that Marquez's humerus bone, which links the shoulder to the elbow, was able to pop out "in all directions" requiring open surgery on the bone and additional work to repair the ligaments.

"One hundred per cent success is not guaranteed by anyone, but after the operation, even with him asleep, we did a stability test… moving the shoulder in all directions and it did not dislocate," Mir added.

"That is a good sign because, when he is awake, the muscles will hold the bone in place more."

The main target is now to get Marquez as fit as possible for the opening 2019 test at Sepang from February 6-8.

Meanwhile, new Repsol Honda team-mate Jorge Lorenzo is also recovering from a more minor operation on his injured right foot.