Olympiacos: Giannis Maniatis
Olympiacos won't be one of the favourites to get through Group A initially, but they will believe that their home form could count for plenty if they keep tight and difficult to break down on the road.
Midfielder Giannis Maniatis is always impressive and important for them, whether in his protective role of shielding the defence or given more licence to break forward in counter-attacks. He can also play full-back, but he is far more effective as a central player.
Maniatis is aggressive, good on the ball, can use space well and has leadership qualities—everything Olympiacos will need in abundance if they are to cause an upset and progress.