The little “box” or bump on the upper back of rugby players’ shirts is a small GPS tracking unit used for performance and fitness data.

What that little box actually is

Teams place a lightweight GPS device between the shoulder blades, either in a built‑in pouch in the jersey or in a tight vest under the shirt.

It looks like a small rectangular lump or handle just above the player’s number, which is what people notice on TV.

What the GPS unit measures

These trackers collect a ton of performance data during a match or training session.

Typical metrics include:

  • Total distance covered
  • Top speed and sprint counts
  • Acceleration and deceleration loads
  • Impacts and physical collisions (via movement patterns)

All that information helps coaches understand how hard each player is working and whether their conditioning is where it needs to be.

Why teams use it

Coaching and sports‑science staff use the GPS data for:

  1. Planning training loads so players don’t overtrain or undertrain.
  2. Adjusting tactics (for example, seeing if a certain position is being overworked).
  3. Monitoring fatigue and injury risk across a long season.

Because the advantages are so big, these devices have become standard in top‑level rugby, to the point that jerseys are now designed with a special pocket just for them.

A quick example

During international tournaments and major club games, just about every player on the pitch will have one of these units in their shirt.

Broadcasters sometimes even mention “GPS stats” like total meters run or max speed, which come directly from those little boxes on their backs.

In short: it’s not a strange design or a handle – it’s a high‑tech GPS tracker driving modern rugby analytics.

Meta description:
Wondering what is the little box on the back of rugby players’ shirts? It’s a GPS tracking device that records distance, speed, and workload, now standard in elite rugby.

Information gathered from public forums or data available on the internet and portrayed here.