Unai Emery reveals Aston Villa injury boost for Olympiacos and gives Emi Martinez update

Former Arsenal manager Unai Emery came back to haunt his former club this weekend, and put an enormous dent in their Premier League title ambitions in the process. But after a first-half where Mikel Arteta's men looked in total control, how did his predecessor completely flip the game around in the second 45? Adam Clery looks at how a slight change of shape, and a massive change of approach, gave us one of the shocks of the season.