The final four have been confirmed with Barcelona, Arsenal, Paris Saint-Germain, and Inter Milan the teams vying to punch a pair of tickets to the final in Munich.

After a brief interlude to decompress from the thrilling quarterfinal round, the Champions League returns this week with a pair of attractive and intriguing semifinals. Below, we look at the biggest X-factors that will help determine which teams advance to play for the coveted title.

Germain, and Inter Milan entertain Europe and the world as the semi-finals of the Champions League begin. All four teams will be dreaming of booking their place in the final in Munich on May 31st.