Prosecutor Gerrie Nel noted that a psychiatrist for the defence said the anxiety disorder she diagnosed in Pistorius could have played a role in his fatal shooting of girlfriend Reeva Steenkamp at his home last February.
Mr Nel also acknowledged that an evaluation of the athlete's state of mind at a government facility could cause the trail to be delayed.
Pistorius claims that he mistook Steenkamp for an intruder when he shot her. Prosecutors say he killed her in anger after an argument.
Judge Thokozile Masipa ordered an adjournment and said she would rule on Mr Nel's request today.
The prosecutor also questioned why the defence asked psychiatrist Merryll Vorster to testify on behalf of the Olympic athlete.
He suggested that the trial is not going well for Pistorius and his lawyers are floating the idea that a disorder contributed to Steenkamp's shooting and that therefore Pistorius bears less responsibility for her death.
In asking for another professional evaluation of Pistorius's mental state, Mr Nel appeared to be trying to ward off any attempt by the defence to say Pistorius should be treated favourably by the court because of a mental condition linked to his disability.