Maradona admitted to hospital in Argentina
"It's not a serious situation and we didn't come for an emergency," Leopoldo Luque told reporters outside the clinic in La Plata, south of Buenos Aires.
Though he gave no details of Maradona's condition, Luque said his patient would undergo a series of medical check-ups.
"He's an elderly patient with many pressures in his life. It's a time when we must help him. It's very difficult to be Maradona," Luque said of the star, who celebrated his 60th birthday on Friday.
The doctor ruled out any link to the coronavirus pandemic, which is ravaging the South American country, much of it still under confinement.
Maradona, who has a history of drug and alcohol abuse and poor health, is considered at high risk of coronavirus complications should he be infected.
He has suffered two heart attacks in the past and contracted hepatitis.
"Diego is fine, but he can be much better. I didn't find him the way I wanted to see him. I had a previous talk with him, I told him: 'Let's go to a clinic to improve a little,' and he said: 'Well, let's go,'" said Luque.
The former Argentina captain, who led his team to triumph in the 1986 World Cup, is currently coach of Argentine SuperLiga club Gimnasia.
Along with Brazil's Pele, Maradona is widely regarded as the greatest player of all time.
He joined his players briefly at the club's training ground on his birthday, but had obvious difficulty walking and had to be helped away by his assistants after staying only 30 minutes.
"It breaks my heart to see him like this," one of his daughters, Giannina, tweeted the next day.
"I didn't go to see him that day, but the day before he was very well," his doctor told reporters outside the clinic in La Plata, where Gimnasia is based.
Maradona went into self-isolation last month after a bodyguard showed symptoms of the virus, though he later tested negative.