Manchester City boss Pep Guardiola admits striker Sergio Aguero has found the last few days difficult following the death of Diego Maradona.
City's record goalscorer was once married to Maradona's daughter Giannina, who is the mother of his son Benjamin.
Argentina forward Aguero also played under Maradona during his time as manager of the national team, including at the 2010 World Cup.
Aguero appeared as a late substitute in City's Champions League win over Olympiacos on Wednesday.
It was just hours before kick-off in Greece that news broke that Maradona, hero of Argentina's 1986 World Cup win, had died.
Guardiola said: "Of course it's difficult for me to talk about his feelings.
"I saw him good but the impact on the day of the game against Olympiacos was hard, especially for his son.
"Of course it was tough, that's normal. He knew Maradona quite well and, for his son, he was his grandfather.
"It is a sad situation, unfortunately, for his family but he's okay."
Aguero is currently easing his way back into action after knee and hamstring injuries. His 12-minute run-out in Piraeus was his first appearance in a month.
Guardiola is confident Aguero will get back to his best but is wary of rushing the 32-year-old, who still needs to build up his match fitness.
"He's going to give us good moments this season," said Guardiola, whose side host Burnley in the Premier League on Saturday.
"He is still not in his best condition but we cannot forget how long his injury was. Then he came back and was injured again.
"In the middle of the season he is a guy who needs to be so sharp to score goals in the box but we don't have doubts."
Aguero is now in the final year of his contract at the Etihad Stadium but Guardiola insists there is no pressure on the player to make a decision over his future.
"He is a guy who deserves, with the club, fair talks to do what is the best for him, for the club, for everyone.
"I have been lucky to play and manage with incredible football players and he's one of them. I've never found a big star like him."
Aguero's return, as well as that of Gabriel Jesus in recent weeks, is timely given City's problems in front of goal this season. In a sluggish start, City have won just three of eight Premier League games and scored only 10 goals.
"It's time to put more players in the box, be positive and sooner or later it is going to happen," said Guardiola.
Australian Associated Press