M ikel Arteta can be forgiven for never missing the chance to remind everyone that these are unprecedented times for Arsenal. As his side prepares to face Atlético Madrid in the decisive act of their second successive Champions League semi-final, it is easy to forget that they have only reached this stage on four occasions in their entire history.

But 20 years after Arsène Wenger’s team edged past Villarreal in the last European match to be played at Highbury, Arsenal have their best opportunity since then to reach a second final after a campaign where they have swept all before them.…