Claudio Ranieri led Chelsea to the Champions League semi-finals in 2004 and pitted his wits against Barcelona coach Frank Rijkaard when he was at Valencia last season.
Here, he gives BBC Sport his insights into the two sides and how they will match up in their Champions League tie on Wednesday...
For me, Chelsea against Barcelona is the Champions League final arrived early.
Along with Juventus and AC Milan, they are the best sides in Europe and it's a shame they have to meet at this stage.
The two teams are very, very different though. Jose Mourinho is like an Italian coach.
He is very tactical and it's difficult to score a goal against his sides. They always have a strong defensive line and are compact, not giving away much space or many chances.
But when their opponents make a mistake, they pounce. They are very fast on the counter-attack.
I would not man-mark Ronaldinho - Makelele can drop back and help the defence
Of course, I know most of Chelsea's players well. I bought Frank Lampard, Petr Cech, Arjen Robben, Joe Cole and Damien Duff and brought John Terry into the side.
I was sure that one day these young players would be champions. Now they are champions and I'm very happy.
I feel like a schoolteacher when his pupils arrive at university. You hand them over to someone else but you are very proud.
My relationship with Mourinho is very good and I'm not jealous of him at all.
Mr Abramovich has told me that Chelsea is my home and any time I want to visit Stamford Bridge or the training ground at Cobham, I will be welcome.
I know Barcelona well from my time with Valencia last season. They are very different to Chelsea. They are less structured and concentrate on keeping possession of the football.
They bought Mark van Bommel in the summer, and have Edmilson back from injury, and they have made them more solid than last year, when Chelsea knocked them out.
But Xavi is injured and he is a fantastic player. His absence is a big blow.
I think Barca must have all their big players - Ronaldinho, Samuel Eto'o, Deco and Lionel Messi - in very good condition if they are to have a chance, because Chelsea have more possibilities for changing players than they do.
A 0-0 draw in this game will not be a disaster for Chelsea
Ronaldinho is an amazing footballer, but I would not man-mark him. Claude Makelele can drop back and help the defence when necessary.
Although Chelsea are more defensive than Barcelona, I don't understand why people like Johan Cruyff say they are boring.
Mr Cruyff is a Dutchman, but I am Italian and Italian managers are very pragmatic.
What is important is to win. Ask the Chelsea crowd if their side is boring. They will say: "No, they are fantastic."
A 0-0 draw in this game will not be a disaster for Chelsea. They could still have a chance.
Finally, there has been a lot of talk about the pitch at Stamford Bridge, which doesn't surprise me. The pitch is very enclosed and the wind doesn't go round the ground.
The pitch needs some air, some refreshment.
Every year they used to change the pitch. I don't know why they haven't this year. Maybe they haven't had time because of all the matches they've had.
Interview by Simon Austin