3. Jack Clifford
Back in 2015, Eddie Jones tipped the versatile Harlequins back-rower as ‘the real deal’ and tipped him to captain England at the 2019 Rugby World Cup.
However, following years of problems, Clifford was forced to retire at the age of 27 because of injury last August.
He won 10 international caps after making his England debut in Jones first game in charge against Scotland at Murrayfield in 2016.
RUCK VERDICT: To think he played over 100 games for Harlequins and 10 games for England in an eight-year career where he was effectively injured for four years shows how valued he was by anyone who coached him. Simply unlucky.