Arsenal vs Aston Villa: Theo Walcott's performance was a lesson for Jack Grealish

One of them is suddenly being touted as a teenage wonder, the other has been through all that and come out the other side, even if some still doubt whether he has reached full maturity. Yesterday Aston Villa’s 19-year-old Jack Grealish learnt a lesson that achievement in football demands far more than one semi-final day in the sun.