The start of the trial was delayed after Sepp Blatter said he was too sick to testify.
He told the court that he couldn't testify due to chest pains.
The 86-year-old whispered that he was having difficulty breathing and that the pain would return.
The Federal Criminal Court in Bellinzona allowed Sepp Blatter to testify on Thursday.
Swiss prosecutors claim that a payment of over two million Swiss Francs was not legal.
Both men deny wrongdoing and say the transfer was a mistake.
The pair were banned from football in 2015.
Lawyers for the two men failed to move the trial to a local court or dismiss the case against them.
A verdict is expected on July 8th.
The defendants could be sentenced to up to five years in prison.