Sergio Aguero fears he won't be able to run at a decent pace again after his cardiac arrest.
The Argentinian was subsequently diagnosed with a cardiac arrhythmia (irregular heartbeat).
Speaking about his health on a Twitch stream, the 33-year-old said: "If I try to play football now, I run out of breath.
"Sometimes I wonder if I will ever be able to sprint again. I just feel like my heart doesn't work properly."