Lionel Messi: The Argentine has scored five goals in six Champions League appearances this season. He previously struggled against Atletico Madrid, but he scored in each of the two meetings in La Liga, so as always, Messi will be a danger. (Francisco Seco/AP)
Cristiano Ronaldo: The Portuguese is coming off a heroic performance in El Clasico as his strike stood as the winner at the Camp Nou. There have been claims that Ronaldo is “declining,” but he leads the Champions League with 13 goals this season. Wolfsburg will definitely have its hands full. (Francisco Seco/AP)
Manuel Neuer: The Bayern Munich goalkeeper may not grab as many headlines as Thomas Muller or Robert Lewandowski, but Neuer is still crucial to Bayern’s success. Porto troubled the Bavarians last year in the quarterfinals at home, and Benfica has been in stellar form, so the 30-year-old will be relied upon if the German champions want to avoid another stunner from a Portuguese club. (Matthias Schrader/AP)
Diego Godin: Godin recently returned to training after missing the past few weeks with a thigh injury. Atletico has kept an astounding six clean sheets in eight games, and since it is facing Barcelona, the team will need the Uruguayan at full fitness if it wants to progress to the semis. (Andres Kudacki/AP)
Blaise Matuidi: With Marco Verratti missing the first leg, there will be even more pressure on Matuidi. The French international has been one of PSG’s most consistent players, but with Angel Di Maria and Javier Pastore also listed as doubtful, the 28-year-old will be crucial on both sides of the pitch. (Jacques Brinon/AP)
Sergio Aguero: Aguero has missed time through injury, but he has still managed to score two goals in five Champions League appearances. The Argentine is Manchester City’s main attacking threat, and he’ll be facing a rocky PSG defence that has looked shaky in their past two games. (Jon Super/AP)
Nicolas Gaitan: Gaitan is one of Benfica’s key players and has been a crucial part in their recent resurgence in Portugal. The Argentine has four goals and three assists in seven appearances in the Champions League. He’ll be central to the Eagles’ plans if they hope to upset Bayern Munich. (Lefteris Pitarakis/AP)
Julian Draxler: Draxler has always shined in the Champions League. Dating back to his debut in the competition with Schalke, the German has recorded eight goals and five assists in 32 appearances. He struck twice in the round of 16 against Gent, and will surely be key to Wolfsburg’s attack against Real Madrid. (Michael Sohn/AP)