Eight more teams will do battle this week as the UEFA Champions League Round of 16 first legs come to a close. A pair of historic clubs will duke it out in London on Tuesday as Chelsea hosts La Liga leaders Barcelona.

Eden Hazard will hope to give the Blues an early advantage in the aggregate, while Barcelona are favorites to advance. Elsewhere this week, Bayern Munich hosts Besiktas while AS Roma travels to Shakhtar Donetsk. Manchester United faces a tricky test as they travel to Sevilla.

Here’s a closer look at this week’s UCL action:

CHELSEA VS. BARCELONA (Tuesday, 2:45 p.m., Fox Sports 1, ESPN Deportes)

Injuries of Note: David Luiz and Tiemoue Bakayoko are likely to miss the clash for Chelsea with respective injuries. Marcos Alonso returns for Chelsea while Ross Barkley is also available. Barcelona will miss Nelson Semedo through suspension, while Philippe Coutinho is ineligible after playing for Liverpool earlier in the competition.

Key to the Game: Barcelona should be able to own possession away from home and can give Chelsea’s backline problems. Possession will be important for Chelsea in order to find the back of the net.

Player to Watch: Chelsea winger Eden Hazard has 15 goals in all competitions this season and will be a huge part of his side’s attack. If they want to have a strong performance at home, Hazard will need to put the team on his back.

Quote: “They are one of the best teams in the world but we are the last champions of the Premier League, we deserve respect,” Chelsea’s Cesc Fabregas said. “We deserve to give it a go. To try and play two good games against them. It has happened in the past. In football, never say never.

BAYERN MUNICH VS. BESIKTAS (Tuesday, 2:45 p.m., Fox Sports 2, ESPN3)

Injuries of Note: Both sides come into this match very fresh with the only long-term absentee being Bayern keeper Manuel Neuer.

Key to the Game: For Besiktas to have a strong chance at a good result on the road, they will need to keep Bayern outside. They have the ability to beat teams through the middle of the field, through a variety of different playmakers in the midfield.

Player to Watch: Brazilian playmaker Anderson Talisca has four Champions League goals this season and 13 overall. He is quick and talented which could be a problem for Bayern’s backline.

Quote: “We know that we are really meeting a top European team who have convincingly won their group,” Bayern defender Mats Hummels said. “They have big names in the team. They also have, as we have seen on the videos, real quality in their game, tactical and individual.

SEVILLA VS. MANCHESTER UNITED (Wednesday, 2:45 p.m., Fox Sports 1, ESPN Deportes)

Injuries of Note: Jose Mourinho expects Marcos Rojo, Phil Jones, and Marouane Fellaini to miss out of Wednesday’s clash. Marcus Rashford, Antonio Valencia, and Ander Herrera all have a chance to play.

Key to the Game: Manchester United used goals in each half to ease past Huddersfield over the weekend. For them to get a result away from home, they will need to attack on the counter against a fast Sevilla side.

Player to Watch: Sevilla striker Wissam Ben Yedder has eight goals in the competition this season, and 17 across all competitions. He is a clinical finisher and is expected to give a United backline problems.

Quote: “For us, it’s all about getting through to the next round,” Sevilla winger Jesus Navas said. “But I know it would be nice for some of the friends I’ve got back in Manchester if we did manage to pull it off and knock out United.

SHAKHTAR DONETSK VS. AS ROMA (Wednesday, 2:45 p.m., ESPN3, Fox Sports 2)

Injuries of Note: Roma will be without Maxime Gonalons, Jonathan Silva, and Rick Karsdorp. Shakhtar come into this match with a fairly healthy squad.

Key to the Game: Shakhtar’s dynamic offensive front should have their hands full with a stubborn Roma defense. For the hosts to get anything going, they will need to keep Roma off of the ball and on the back foot.

Player to Watch: Facundo Ferreyra is Shakhtar’s playmaker and has over 20 goals in all competitions this season. For the hosts to have any chance at finding the back of the net, the Argentinian midfielder will need to be at his best.

Quote: “The team have been preparing very well. The motivation is great. We know that we are facing a crucial game for both the whole team and the fans, and we want to please them,” Ferreyra said. “I suppose the chances are equal – 50-50. Roma are a very good team but we believe in our strength and condition.”