Atlético Madrid and Benfica face each other on Wednesday night in the second match of the UEFA Champions League group stage in a fight for the top spot in Group C.
After victories for both teams in their opening encounters, it could be one of the most intriguing games on Wednesday's journey through European football.
It's interesting that while both teams are constants in European competition, it will be the first time that Atletico and Benfica face each other in an official game.
Benfica have quite a number of players who once wore the Rojiblanco jersey.
Silvio, Pizzi, Raul Jimenez and the injured Toto Salvio all once represented Atletico Madrid during their respective careers. None of them have earned consistent playing time in Rui Vitoria's initial XI, however, with Pizzi being the most used player of the four and Raul Jimenez the only one to have scored with just the one goal.
In the colchoneros squad the only player with Benfica history is Guilherme Siqueira. He played for the Lisbon-based side for one year after moving there on loan from Granada for the 2013-14 season.
Ex-Valencia forward Jonas is Benfica's top scorer with 7 goals in 8 appearances this season, although none of them have come in the Champions League. The experienced and skilled Brazilian striker is a mainstay in Benfica's XI with Mitroglou or Raul Jimenez joining him at centre forward.
Nico Gaitan, who was linked with Atletico several times during previous transfer windows, rules the assists category for Benfica. The attacking midfielder is the most creative and skilled player in Benfica's squad and you can be sure that Simeone has advised his defenders of Gaitan's qualities.
Although he is not a consistent fixture in Benfica's XI, Godin and Gimenez will have to be aware of Talisca's ability if he is to play.
4-4-2 or 4-3-3?
Taking into account reports from Atletico's final training session before the game, you can intuitively decide what Simeone is planning on doing. The defense won't change and Tiago, Gabi and Óliver will feature as midfielders. This way, we only have one doubt: if Griezmann will play as a striker or whether he will feature as a midfielder with Correa and Jackson at the top of the formation.
We could see the same tactical system than we saw in Atletico's first game against Galatasaray. If that is the case, Óliver would occupy the spot of Koke and Griezmann or Correa would play the role that Vietto filled in that game. Hence, Atleti would form a 4-3-3 with Griezmann playing as a centre forward between strikers and midfielders.
On the other hand, if Griezmann plays as a wide midfielder, we will probably see the usual 4-4-2 formation and the vacant wide midfield spot would be occupied by Óliver Torres. This would not be a new experience for either player, although they have been more convincing when they fill more central roles in the team.
We don't know in what capacity, but we will probably have the first opportunity to see Angel Correa in the starting XI. With some very good performances in his opening few appearances for the club, he has looked very impressive and will look to continue that form on Wednesday night against Benfica.
In: Oblak, Moyá, Juanfran, Godín, Giménez, Savic, Filipe Luis, Siqueira, Tiago, Gabi, Saúl, Óliver, Carrasco, Correa, Luciano Vietto, Griezmann, Jackson and Torres.
Out: Gámez, Lucas, Thomas (tactical) and Koke (injury).