Diego Maradona was taken to a hospital in La Plata, Argentina on Monday for anemia and dehydration.
He was then transferred to a hospital in Buenos Aires and early on Tuesday, Luque said his condition had improved.
But later on Tuesday, a blood clot was discovered in the brain at the X-ray and it was decided to operate.
Two heart attacks
The Argentine has previously suffered two heart attacks and he has also had liver problems.
Diego Maradona is now the coach of the Argentine Gimnasia y Esgrima. He met the players at the team's training facility in connection with his 60th birthday last Friday, but is said to have had major problems walking and only stayed for half an hour.