FC Barcelona striker Leo Messi scored a hat-trick a fortnight ago to ruin former Barca coach Pep Guardiola's return to the Camp Nou Stadium with Manchester City as Barca defeated the English side 4-0.

Now Tuesday sees Barca play the return leg in Manchester knowing a draw will all but book their place in the knockout round of the Champions League, while leaving City with a mountain to climb.

Barca travel without the injured defensive trio of Gerard Pique, Jordi Alba and Jeremy Mathieu (who is suspended anyhow for the game), and midfielder Andres Iniesta, who has a knee injury, however, Sergio Busquets should be fresh after being rested for the weekend 1-0 win over Granada.

Speaking in an interview with the English 'Sun' newspaper which was reprinted in Spanish daily, Diario AS, Messi compared Guardiola's Barca with that now coached by Luis Enrique.

"The system of Barcelona is something that everyone knows, few clubs have that, but each coach has different ideas and applies them as he sees fit," he said.

"With Luis (Enrique) maybe now we are a bit more aggressive when we attack at speed, whilst with Pep we used counterattacks less," he explained.

Messi also mentioned Manchester City striker and friend, Kun Aguero, comparing him to Barca teammate Luis Suarez. He said Aguero was "a very simple and easy going person, as is Luis... they are different but either of them can decide a game," he commented.

Finally, Messi said he was confident Guardiola would succeed in Manchester: "City are a great team. They have been a great team every time we have faced them but now with Pep they will grow more through his work," he concluded.

Tuesday also sees Atletico Madrid entertain Russian side Rostov, knowing a win will see them into the last 16 of the competition.