Hussey or 'Womble' as he is nicknamed for playing for AFC Wimbledon, was given compassionate leave by City boss Aidy Boothroyd and returned to London on Friday.
Speaking to the CT, Boothroyd said: "Chris has had to go back because his mum has had a heart attack.
"I sent him home on Friday and hopefully everything will be all right and she will be OK. It is a mild heart attack but a heart attack is a heart attack."