Operational definitions
| Training session | Team training that involved physical activity under the supervision of the coaching staff |
| Match | Competitive or friendly match against another team. |
| Injury | Any physical complaint sustained by a player that resulted from a football match or football training and led to the player being unable to take full part in future football training or match play. |
| Ligament injury | Traumatic distraction injury to a ligament. |
| Muscle injury | Traumatic distraction or overuse injury to a muscle. |
| Injury incidence | Number of injuries per 1000 player hours ((Σ injuries/Σ exposure hours)×1000). |
| Injury burden | Number of lay-off days per 1000 player hours ((Σ lay-off days/Σ exposure hours)×1000). |
| Squad availability | The average percentage of players available for training and match selection (eg, not absent due to injury, illness, national team duty or other reasons). |
| Injury absence | The average percentage of players who were absent from trainings and match selection due to injury. |
| Reinjury | Injury of the same type and at the same site as an index injury. |