Everything you need to know ahead of Wednesday's UEFA Champions League semifinal at the Parc des Princes as Arsenal look to mount a comeback against PSG.

Felix Zwayer has been appointed as the referee for Arsenal 's Champions League semi-final second-leg decider against Paris Saint-Germain on Wednesday night. UEFA have announced that the German official, 43, will take charge of the return leg in Paris, with Arsenal a goal down on aggregate following last week’s narrow defeat at the Emirates Stadium.

The penultimate matches of this season's UEFA Champions League will take place in Milan and Paris this week, where the final four teams standing will target a spot in this month's final as both semifinal ties still hang in the balance.