According to Ugandan television station NTV, Massa was shot at by police in a road incident.
Massa is said to have hit a police motorcycle before speeding off which forced police to retaliate.
The report further suggests that a woman who was a passenger in the car driven by the well-travelled forward died on the scene after the alleged confrontation with the police.
Massa is recovering at Gwatiro Clinic in Bweyogerere.
The 31-year has also turned out for Al-Masry, El-Shams, Jomo Cosmos, Itesalat, Yenicami Agdelen and University of Pretoria.