#4 Alessandro Costacurta
Italian and AC Milan legendary defender, Alessandro Costacurta is the fourth oldest player to play in the UEFA Champions League, aged 40 years and 213 days.
Milan played against Greek side AEK Athens in 2006 and lost 1-0 away in a group stage fixture in 2006. However, both sides managed to progress to the next round of the tournament, with Milan topping the group.
Milan went on to win the Champions League but Costacurta didn't play in the team thereafter. The Italian began his career in 1986 and alongside Paolo Maldini, Wesley Barresi and Mauro Tassoti created one of the most formidable defenses in the world and won 5 European Cups with Milan in all.
The defender also won 7 Serie A titles and finished the 1994 World Cup with Italy as a runner-up. Costacurta was a great defender and spent his entire career with Milan, making over 650 appearances for the club across all competitions.