"It is very, very, very likely that he will testify based on the nature of the defence that he is relying on," University of Cape Town law lecturer Kelly Phelps said on the eve of the resumption of the trial.
It was common practice in South Africa for the defence to call the accused first, she said.
Pistorius needed to testify to prove that he mistakenly believed Steenkamp was an intruder.
"The only way to suggest some evidence is for the accused to take the stand. How else would his subjective state of mind be tested," said Phelps.
Wits School of Law Professor Stephen Tuson said Pistorius risked conviction if he did not testify.
"If he does testify, he should testify first to prevent an accusation that he tailored his evidence," said Tuson.
"The defence do not want the prosecution to say the evidence of the accused was tailored to match the evidence of the witnesses."
Criminal law expert William Booth said it was important to remember the defence had no burden of proof.
"We know that Oscar shot four times into a toilet - he thought it was an intruder. That was what he said during bail," said Booth.
"Looking at all the evidence the State presented, he is going to have to give evidence and be subjected to cross examination."
The State closed its case on Tuesday after it called 21 of the 107 witnesses on its witness list.
The witnesses included Pistorius's neighbours, a security guard at his estate, the pathologist, ballistic expert, cellphone expert, Pistorius's ex-girlfriend and former friends.
Pistorius is on trial for the murder of Steenkamp, who was shot through the locked toilet door of his Pretoria home on 14 February last year.
He said he had mistaken her for an intruder.
However, the State said the murder was premeditated.
He has pleaded not guilty and in his plea statement denied they had argued shortly before the shooting.
He also faces two charges related to contraventions of the Firearms Control Act.
On Tuesday his legal team said he would testify in his own defence.
"I don't think we have a choice. The question is when," a member of Pistorius's legal team, Brian Webber, at the time.
After prosecutor Gerrie Nel indicated on Tuesday that the State closed its case Advocate Barry Roux for Pistorius asked for the adjournment to see which witnessed the defence could possibly call.
Tuson said Pistorius's defence team had various options including applying for an acquittal in terms of Section 174 of the Criminal Procedure Act.
"If the defence feels that the prosecution has not succeeded in bringing sufficient evidence in conviction of the accused they can bring an application," he said.