Referees
Ranking
The UEFA Refereeing Unit is broken down into five experience-based categories. A referee is initially placed into Category 4 with the exception of referees from France, Germany, England, Italy, or Spain. Referees from these five countries are typically comfortable with top professional matches and are therefore directly placed into Category 3. Each referee’s performance is observed and evaluated after every match; his category may be revised twice per season, but a referee cannot be promoted directly from Category 3 to the Elite Category.[59]
Appointment
In co-operation with the UEFA Refereeing Unit, the UEFA Referee Committee is responsible for appointing referees to matches. Referees are appointed based on previous matches, marks, performances, and fitness levels. To discourage bias, the Champions League takes nationality into account. No referee may be of the same origins as any club in his or her respecting groups. Referee appointments, suggested by the UEFA Refereeing Unit, are sent to the UEFA Referee Committee to be discussed and/or revised. After a consensus is made, the name of the appointed referee remains confidential up to two days before the match for the purpose of minimising public influence.[59]
Limitations
Since 1990, a UEFA international referee cannot exceed the age of 45 years. After turning 45, a referee must step down at the end of his season. The age limit was established to ensure an elite level of fitness. Today, UEFA Champions League referees are required to pass a fitness test even to be considered at the international level.[59]