Sheikh Abdulla claims Mr Jackson reneged on an agreement
Michael Jackson could be made to fly to the High Court in London to testify in a breach of contract case, despite his doctor saying he is unfit to travel.
The court heard the singer was waiting on test results about an unspecified condition and that "even in a best-case scenario it would be unwise to travel".
However, lawyers for Sheikh Abdulla Bin Hamad Bin Isa Al-Khalifa said he could be "bandaged up" and appear in person.
The King of Bahrain's second son claims Mr Jackson reneged on a music deal.
He is suing the performer for £4.7 million, claiming that under the agreement, an album, stage play and candid autobiography were to be produced.
Mr Jackson's lawyer, Robert Englehart, has asked that his client can give his testimony by video link from the US.
Mr Englehart showed the judge, Mr Justice Sweeney, a letter from Mr Jackson's doctor which was not read out in open court.
The judge told the court the letter suggested that Mr Jackson "may or may not have a condition" and that the doctor was waiting for test results.
The doctor has advised that Jackson would not be fit to travel regardless of the results.
Sheikh Abdulla is due to give evidence on Thursday
But medical experts consulted by the defence team said that pathology results relating to such a condition would usually take 48 hours, Sheikh Abdulla's lawyer Bankim Thanki said.
As Mr Jackson had seen the doctor ten days ago, Sheikh Abdulla was "rightly sceptical" about the doctor's letter, Mr Thanki added.
The defence team's experts also said that, even if test results were positive, it would be possible for Mr Jackson to fly to London with "suitable dressings".
Mr Justice Sweeney has adjourned the case until Thursday when he will decide whether Jackson must give his evidence in person or by video link.
Also on Thursday, Sheikh Abdullah is scheduled to give evidence against Mr Jackson.
And the singer's former nanny Grace Rwaramba, who was due to fly into London from the US on Tuesday night, will appear for Mr Jackson.
If Mr Jackson is allowed to give his evidence by video link, it will probably take place at 1400 GMT on Monday and Tuesday, the judge added.
Mr Thanki said Sheikh Abdulla felt "a strong sense of personal betrayal" after forming "a close personal relationship" with the singer.
The sheikh invited Mr Jackson, his children and personal staff to stay in Bahrain in June 2005 following his acquittal on child abuse charges in the US.
The King of Bahrain's son said he had planned to revive the singer's career with songs he had written himself.
These included a charity single in aid of the victims of Hurricane Katrina that was recorded but never released.
Mr Jackson contests Sheikh Abdulla's claims, saying there was no valid agreement and that the case was based on "mistake, misrepresentation and undue influence".
He has said no project was ever finalised and that any payments made to him were "gifts".
The case, which is being tried in London by mutual agreement, is due to wrap up by the end of the month.