Here are four things to keep an eye out for in the Champions League this week.

The first leg of this season's Champions League semi-finals is this week.

This is what to look out for during the action.

Match of the Week

There isn't much separating these two semi-finals, as each game offers something unique. However, if we had to pick one, Arsenal's match against Paris Saint-Germain would win by a nose.

The Gunners will host this season's greatest European side at the Emirates, in a match that will pique the interest of even the most sceptical football fan.

Luis Enrique's PSG have been an absolute revelation this season, sweeping the Ligue 1 title and, since the final week of the League Phase, steamrolling everyone before them on the continent.

However, what appeared to be a simple two-legged victory for France a few weeks ago has taken on a new dimension.

PSG lost their first domestic encounter of the season over the weekend, as Nice prevented the capital club from remaining unblemished in the league.

This comes on top of PSG's surprise defeat to Aston Villa in the second leg of their quarter-final two weeks ago.

They may have been a winning machine in 2024/25, but there is a clear weakness that Arsenal should be able to exploit in front of a loud home crowd.

When you consider the north London team's stunning success over Real Madrid in the previous round, the return of Bukayo Saka, and the fact that there was no Premier League match to cope with over the weekend, a slim possibility has changed into a very good one for the English club.

Whatever happens, this will be a game you absolutely cannot miss.

🔎 Team to watch.

One down; two to go.

Barcelona won the first leg of their quest for a treble this season with an incredible extra-time victory over Real Madrid in the Copa del Rey final.

The main question now is whether the Blaugrana can recover from their spectacular triumph over their arch-rivals and prepare for a key game against Inter.

If this season's statistics provide any indication, the quick answer is yes.

Hansi Flick's team is undefeated at home in the Champions League this season and has not lost in Montjuïc in any competition since December, a 14-game streak.

The Blaugrana boast two of the most in-form attackers in the world in Lamine Yamal and Raphinha, while Pedri's performance in Saturday's final has many questioning whether he is now Europe's top midfielder.

With goalkeeper Wojciech Szczęsny's performance, the Catalan club has the potential to win their first European crown in ten years.

🔥 Player to watch.

For Inter to win the game in Barcelona on Wednesday, Lautaro Martínez must be at his peak performance.

Over the last year, the Argentina international has quietly established himself as one of the world's top strikers.

In a last-round shootout with Harry Kane, Lautaro emerged victorious, scoring in the first leg at the Allianz Arena and again on the return to Milan.

In only 650 minutes of Champions League action this season, he has scored eight goals.

That equates to one strike every 81 minutes, the best goal-to-minute ratio of any player who advanced to the knockout stages.

The Nerazzurri won't mind if the goals arrive, as long as Inter's fox in the box packs his scoring boots for the journey to Spain.

📊 A fascinating statistic

This will be Arsenal's sixth meeting with Paris Saint-Germain, with the Gunners unbeaten in the previous five games (W2, D3).

Arsenal are the French side's most frequent opponents in European competition, and they have never won.