4. Alan Shearer
Retired age: 30
Though he played on for Newcastle United until the ripe old age of 36, he hung up his boots at international level far too soon just after England’s elimination from Euro 2000. Whilst on 30 goals in 63 games for the Three Lions, Shearer could easily have caught up to record scorer Bobby Charlton on 49 strikes, but sought to cut his international career short early in order to prolong his time at St James’ Park.