The last four teams standing return to play in the UEFA Champions League this week for the first leg of the semifinals, when some of Europe's top sides will begin to map out their route to the final on May 31 at Munich's Allianz Arena.

Arsenal Receive Timely Injury Boost Ahead of Crucial PSG ClashAs the UEFA Champions League semi-final looms, Arsenal have been given a significant lift with two key players returning to fitness ahead

Merino missed the Gunners’ most recent match - against Crystal Palace last Wednesday - and was a doubt for the first leg of Arsenal’s semi-final against PSG at Emirates Stadium on Tuesday. The Spaniard, however, took part in training on Monday afternoon and is expected to be fit for the game.