With Sergio Aguero announcing his retirement due to heart issues, here is a look at 10 other footballers who were forced to retire.
The Argentine announced his retirement at a special ceremony at the Camp Nou on Wednesday after advice from doctors.
"I have decided to stop playing professional football. It is a very difficult moment. The decision I have made, I have taken it for my health," Aguero said on Wednesday.
Click through the gallery above to see 10 footballers who were forced to retire
One of the most recent cases occurred in 2017 when former Tottenham Hotspur midfielder Ryan Mason fractured his skull in a game against Chelsea during a head-to-head collision with Gary Cahill.
Mason was out for the rest of the season and was forced to retire a year later at the age of 26 after medical advice.
Kaizer Chiefs also lost one of their talented youngsters to early retirement as Wismeman Meyiwa was forced to hang up his boots at the age 19 after injuries from a car accident.
Some other notable players included former Liverpool star Jamie Redknapp and France's 1998 World Cup winner Emmanuel Petit.
Here are some footballers who have collapsed on the pitch while playing