Listen to Sportsound and follow live text updates of Celtic's final league phase fixture in the Champions League against Aston Villa.

W ith the UEFA Champions League about to enter its knockout phase next week after the final round of league phase play last week, Europe's top clubs had big decisions to make rega

The Champions League knockout play-off begins on Tuesday night, with 16 teams battling to join the already qualified eight sides in the next round. The revamped format has seen the top eight in the group stage head straight into the last 16 of the competition.