Marquez broke the pinky finger on his left hand after suffering the fall whilst dirt track racing and was operated on in a Barcelona hospital soon after.
"He showed up with a deformity in the left pinky on his left hand and scans revealed a fracture," Doctor Xavier Mit, who carried out the surgery told Spanish sports daily AS.
"Therefore we decided to treat the injury, as we would with any other patient, by fixing a titanium plate to his finger.
"That allows us to start the recovery period in 24 hours and to have the chance to run at the Spanish Grand Prix in Jerez."
Marquez is only fifth in the world championship standings after three races this year.
After a fifth-placed finish in the opening race of the season in Qatar, he won the Grand Prix of the Americas in Austin, but a crash towards the end of the Argentia Grand Prix last weekend left him 30 points adrift of championship leader Valentino Rossi.
Marquez's Honda teammate Dani Pedrosa is also currently sidelined due to a forearm injury.