Soccer referees are responsible for keeping up with some of the world’s fastest athletes, often covering more than 6 miles during a single professional match. While fans usually notice the referee’s brightly colored jersey, there’s much more to the uniform than meets the eye.
From compression clothing to advanced tracking technology, referees wear several pieces of equipment underneath their shirts to stay comfortable, communicate effectively, and perform at the highest level.
Compression Shirts and Base Layers
The most common item worn underneath a referee’s jersey is a compression shirt or moisture-wicking base layer. These garments are designed to:
- Keep officials cool in hot conditions by wicking away sweat.
- Provide warmth during cold-weather matches.
- Reduce chafing caused by constant movement.
- Offer light muscle support throughout the match.
Depending on the weather, referees may wear either short-sleeve or long-sleeve compression tops beneath their jerseys.
GPS Tracking Vests
Professional and international referees often wear a lightweight GPS performance vest underneath their shirts. The vest holds a small tracking device positioned between the shoulder blades that records valuable performance data, including:
- Total distance covered
- Sprint speed
- Running intensity
- Workload throughout the match
- Heart rate (on compatible systems)
These statistics help referee organizations monitor fitness levels, evaluate performance, and prepare officials for future matches.
Referee Communication Systems
Top-level referees use wireless communication systems that allow them to stay in constant contact with assistant referees and the video assistant referee (VAR) team.
The communication equipment typically includes:
- A wireless earpiece and microphone.
- A small radio transmitter.
- A battery pack secured under the jersey or attached to the waistband.
This technology enables officials to discuss fouls, offside decisions, and other key incidents in real time without stopping play.
Heart Rate Monitors
Many professional referees also wear heart rate monitors during matches or fitness testing. Depending on the system, this may be a traditional chest strap or a newer optical sensor integrated into their performance equipment.
Monitoring cardiovascular performance helps officials maintain the fitness standards required for elite competitions.
The Referee Jersey Is Designed for Function
The official referee shirt also includes several practical features that fans may overlook.
Most jerseys feature front pockets used to carry:
- Yellow and red cards
- A referee notebook
- A pencil or small writing tool
- Match coin for the pregame toss
Some professional jerseys are also designed to accommodate communication equipment and routing for headset cables.
What Do FIFA World Cup Referees Wear Under Their Shirts?
Officials working major international tournaments such as the FIFA World Cup typically wear multiple layers of specialized equipment underneath their jerseys. A standard setup often includes:
- A compression base layer
- A GPS tracking vest
- A wireless communication harness
- Heart rate monitoring equipment when required
These tools help referees maintain peak performance while covering significant distances and making split-second decisions throughout 90 minutes or more of high-intensity soccer.
Final Thoughts
Although most fans only see the referee’s jersey, professional soccer officials rely on a range of modern equipment underneath their shirts. Compression clothing improves comfort, GPS technology tracks performance, and communication systems ensure seamless coordination between the referee crew and VAR.
Together, these innovations help referees keep pace with the game while making accurate decisions at every level of professional soccer.