Former Real Madrid and Barcelona coach Raddy Antic says Branislav Ivanovic is key for Chelsea in their Champions League semi with Barca.

Antic says fellow Serb Ivanovic can use his considerable physical presence to put the frighteners on Barcelona's sometimes vulnerable rearguard.

Antic told the Sunday Mirror: "Not often, but sometimes Barca wobble. Where I see a big chance for Chelsea is at set-pieces. Barca do have problems in their defence at times, and Chelsea just have to be positive from the very start.

"Ivanovic is a threat that's very hard to deal with."