Former Barcelona captain Carles Puyol has warned his side that they will need to be at their best if they are to beat Chelsea to a place in the Champions League quarter-finals this evening.

Chelsea will travel to Camp Nou hoping for a repeat of their 2012 heroics, when they recorded a memorable 2-2 draw with 10 men in the second leg of their semi-final, en route to lifting the trophy for the first time.

Antonio Conte's side are once again the underdogs having been held to a 1-1 draw in the first leg at Stamford Bridge, but Puyol is wary of the threat Chelsea pose on the counter-attack.

"After the first leg, I think Barcelona are the favourites but you can't be sure. Chelsea have shown that they are a very organised team with clear ideas about how they want to play and players up front who are very dangerous and very quick," he is quoted as saying by Sky Sports News.

"They can hurt you a lot on the counter-attack, so Barcelona will have to put in a serious performance and try to score a goal because if they don't Chelsea could hurt them on the counter.

"The difference (from the 2012 clash) is that we lost 1-0 in London so we had to win. We went out to attack and were 2-0 up, after that they made it 2-1. We did all we could to score another goal but Fernando [Torres] scored the second on the counter-attack and eliminated us.

"Now, I think Chelsea will play a similar game: very strong in defence and look for counter-attacks. For Barcelona, the advantage they have is that with the 1-1 draw they will go through with a 0-0."

Barcelona are bidding to reach the quarter-finals of the competition for an unprecedented 11th season in a row.