Tenerife and Andorra were drawing 2-2 seven minutes into stoppage time when the incident occurred.
Owono ran towards the centre circle to clear a long ball when his knee appeared to collide with De Miguel.
The striker lay motionless on the pitch as medical staff treated him before he was taken by ambulance from Tenerife’s Estadio Heliodoro Rodriguez Lopez to hospital.
Owono was sent off and the match was abandoned.
The goalkeeper, who had over 30,000 followers on Instagram on Tuesday morning, has since deactivated his account.
Police in Spain opened a routine investigation into possible involuntary manslaughter following De Miguel’s death.
Under Spanish law, any death that is deemed non-natural automatically triggers a judicial inquiry.
Owono has made 47 international appearances for Equatorial Guinea.
The Equatoguinean Football Federation said in a statement on Tuesday the 25-year-old was going through a “situation of profound sorrow and grief”.