Real Madrid legend Roberto Carlos feels Xavi is the most important player at Barcelona.
Roberto Carlos feels if Xavi can be silenced, so can Barca.
The Anzhi player-coach explained: "Barcelona is highly dependent on Xavi. To play against Barcelona you must first try to silent this guy, who is the reference.
"Xavi is a genius. He has a bit more than others, but people do not value him as they should."