Sterling left England’s World Cup squad on Sunday and returned to London after the terrifying ordeal.
As a result, Sterling missed England’s 3-0 last-16 win over Senegal and looks set to miss the rest of the World Cup in Qatar.
A spokesperson for Sterling said he was ‘shaken’ by the news and wanted to return to London as soon as possible as he was ‘concerned for the well-being of his three children’.
Koulibaly was asked about his Chelsea team-mate’s departure from Qatar after Senegal’s World Cup exit and said: ‘I really didn’t know. I’m really surprised.
‘I hope his family is good. Now I will call him and see what happened to him. But I hope he will be good and his family is good.’
England boss Gareth Southgate, meanwhile, said: ‘Sometimes football isn’t the most important thing and family should come first.
‘We want to give him that space and we will see over the next few days how that develops.’
England, who topped Group B before knocking out African champions Senegal, face World Cup holders France in the quarter-finals on Saturday.
The Three Lions are through to the last-eight after an emphatic 3-0 win over Senegal, in which Jordan Henderson, Harry Kane and Bukayo Saka got on the scoresheet.
West Ham midfielder Declan Rice starred in England’s victory and said of Sterling’s absence: ‘I saw him at breakfast this morning then the manager said he had the difficulties at home so we’ve all sent him a message.’
Sterling is the second England player to leave the squad in Qatar after Arsenal defender Ben White returned home for personal reasons.
Defending champions France booked their place in the World Cup quarter-finals after beating Poland 3-1 prior to England’s win.
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