The 29-year-old was reportedly in the back of a taxi on Thursday night in Amsterdam after attending a concert, before the car hit a lamp post.
Unconfirmed reports claim the forward has fractured a rib, while the Premier League title-chasers have confirmed that Aguero "was in Holland on his day off and has sustained injuries".
Dutch police claim two people have been taken to hospital after the incident and Aguero's former club Independiente tweeted to send their support.
They tweeted: "Strength and prompt recovery. Everyone @ Independiente is with you in this difficult moment."
A possible injury to Aguero could give Gabriel Jesus a starting role in the coming months, while Leroy Sane and Raheem Sterling will also be looking to play through the middle if needed.
The injury adds to Pep Guardiola's problems, with left-back Benjamin Mendy on the sidelines with a anterior cruciate ligament injury.