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Sami Hyypiä wore the number 4 jersey during his time at Liverpool. The Finnish defender joined the Reds in 1999 and quickly became a key player in the team's success. He was known for his aerial prowess, leadership, and consistency. Hyypiä spent 10 seasons at Anfield, making over 400 appearances and winning several major trophies, including the UEFA Champions League in 2005.