In the past, this fixture has provided the kind of matches that every sporting professional would want to be a part of, a contemporary classic that has lived up to everyone's expectation. And when Chelsea travel to Barcelona next week, there is no reason to consider that it will be anything different.Up against Barcelona on the 21st of February at Stamford Bridge in the 1st leg of the Champions League Round of 16, Chelsea played a nearly flawless game. It may be considered over the top to praise the Blues for a 1-1 draw but the way in which they stopped the Catalan giants with their tactical brilliance deserves appreciation.No team has beaten Barcelona at Camp Nou this season and The Blues will need to be at their vigorous best in order to have a chance to beat the Blaugrana. Their struggles in the Premier League will have to be put aside if they are to go further in this competition.If anyone discards the South London giants' chances of a win because of their poor Premier League form, it should be at their own peril.Here are the five reasons why Chelsea can beat Barcelona at the Camp Nou:#1 Barcelona's mid-field crisisWho will replace Iniesta in the 2nd tie at Camp Nou?Chelsea must be ecstatic by the news that the Catalans giants will face Chelsea in the reverse fixture of round-of 16 of the Champions League, probably without Andres Iniesta.Iniesta is a key figure in the Barcelona lineup and was instrumental in Barcelona's 1-1 draw at the bridge when they travelled here. He got better with time in that fixture, and was the provider for Lionel Messi to neutralize Willian's goal.Barcelona have never been at their best when Iniesta is missing from their starting XI. Atletico Madrid started dominating Barcelona after Iniesta limped off last week in their La Liga fixture. If Atletico are capable of doing it, Chelsea - with all their technically gifted players - have as good a chance, if not better.Also, Barcelona have drawn just 2 games (Against Celta Vigo and Getafe) out of 20 games at home this season, and the Getafe game is the one Iniesta did not feature in. Such is the influence of Iniesta for the Catalan giants.[INJURY NEWS] @andresiniesta8 has a hamstring injury in his right leg. More tests are needed to find out the extent of the problem #BarçaAtleti pic.twitter.com/2rhv79AekT— FC Barcelona (@FCBarcelona) March 4, 2018The Barcelon boss Erneste Valverde has aadmitted that he doesn't know how how to fill Iniesta's void in the playing XI, and frankly, who can? With Andre Gomes constantly inconsistent and Paulinho going through a rough patch of form, Barcelona are nowhere near to solving the issue.The home team is also without the support of Philippe Coutinho, Iniesta's natural replacement, as he is cup-tied for the Champions League. Under UEFA's rules, no player can play for more than one club in a competition in a single season.Chelsea can make use of this uncertainty at Barcelona camp to their advantage and exploit a vulnerable midfield.