The 26-year-old, who joined City for £40 million in 2020, netted his first Champions League goal in his side's 6-3 win over RB Leipzig on Wednesday evening.
The Dutch defender played the full 90 minutes against the German side, as he partnered Rúben Dias in the heart of defence, and opened the scoring by heading in from Jack Grealish's corner just after 15 minutes of action.
However, Aké shared the news of his father passing in a heart-breaking message on Instagram following the victory, with the centre-half stating that the unfortunate death happened only a few minutes after his opener against Leipzig.
Ahead of City's Premier League clash against Southampton on Saturday, Pep Guardiola offered his and the entire club's support to Aké, who is set to start against the Saints with both John Stones and Aymeric Laporte out injured.
"Nathan (Aké) has shown his personality. We are concerned, we are sad. Our condolences to his mother and brother and family and friends, his fiancée," said the Spaniard, as quoted by Daniel Murphy of Manchester Evening News.
"All we can say is we are there for him (Aké). We tried in the last hours to let them feel how close we are to be with him. I'm pretty sure we will be ready and tomorrow to fight for us."
The defender wrote on Instagram, following his side's mid-week win: "The past few weeks have been the toughest of my life, my dad has been very ill and there was no more treatment possible.
"I was lucky to have a lot of support from my fiancé, family and friends. Yesterday after a difficult time I scored my first Champions League goal, and only a few minutes after he passed away peacefully with my mum and brother by his side.
"Maybe it was meant to be, watching me play always made him proud and happy. I know you're always with me, you will always be in my heart and this one was for you dad."
We're sending all of our thoughts, prayers, and love to Nathan and his entire family at this difficult time.