Ronaldo played for United from 2003-09 and turned into a superstar under the guidance of then-manager Alex Ferguson.
United is just one game away from registering their first title win under Ole Gunnar Solskjaer.
Manchester United is currently in the second spot in the Premier League standings and the Red Devils have also managed to enter the finals of Europa League.
Wenger, during his first decade in charge of Arsenal, was vying for English football supremacy with a Manchester United side under the control of Ferguson.
McLeish begins his second spell in charge of Scotland when Costa Rica visit Hampden in a World Cup warm-up friendly.
Arsene Wenger will be in charge for a record 811th Premier League game, passing the mark previously set by Alex Ferguson.
Pep Guardiola says Manchester City were always his first-choice club when he decided to come to the Premier League, despite Sir Alex Ferguson's attempt to lure him.