• German referee sent off Manchester United's Nemanja Vidic
• Chelsea host Barça in semi-final first leg on Wednesday
The German referee Felix Brych will take charge of Chelsea's Champions League semi-final first leg at Stamford Bridge.
The 36-year-old, who has a doctorate in law, also officiated Chelsea's last-16 second-leg comeback against Napoli.
Brych, who is renowned as a disciplinarian, controversially sent off Manchester United's captain, Nemanja Vidic, in the Premier League champions' group-stage fixture with Otelul Galati in Romania. He also dismissed Peter Crouch for two bookable offences when Tottenham lost 4-0 to Real Madrid in last season's quarter-final first leg.
Chelsea's games against Barcelona since 2005 have been dogged by refereeing controversy with Anders Frisk and Tom Henning Ovrebo taking charge of two of the most volatile.