Markus Merk has been appointed as referee for Tuesday's highly-charged Champions League fixture between Barcelona and Chelsea in the Nou Camp.
The German official, a practising dentist, is one of the most experienced in Europe and handled the Euro 2004 final between Greece and Portugal.
Barca lead the Round-of-16 tie 2-1 but when the teams met at the Nou Camp last year Swedish referee Anders Frisk was criticised by Blues coach Jose Mourinho.
Frisk subsequently retired after receiving death threats thought to have come from fans of the English club.
