An Achilles tendon rupture is often obvious. You know if you have done it, or at least, be very suspicious that you have done it.
The most obvious symptom is a loss of power in the calf muscles with a sudden onset of pain, though a few are for some reason not that painful. You may hear an audible snap that is a give away that there might be a tear. If someone was videoing your game, then what it looks like on video is obvious.
A typical test that is done is to raise up onto the toes using the calf muscles. If the Achilles tendon is ruptured, then you can’t do it on the side of the rupture.
If you lay face down and get someone to squeeze your calf muscles, the foot normally moves as the calf muscles are connected to the foot via the Achilles tendon. If the foot does not move when the calf muscles are squeezed, then there is a good chance that it is ruptured. This is called Thompson’s Test.
While it is generally obvious to know if the Achilles tendon ruptures, imaging is still often done to make the final diagnosis.