The first week of the federal FIFA trial featured revelations about corporate bribes, government corruption and vote-buying schemes.

It ended with a debate about one defendant’s skin condition.

On Friday afternoon, after the judge had sent the jury home for the weekend, the prosecutors who spent the week detailing corruption in international soccer switched course and argued that two apparent throat-slitting gestures made in court by Manuel Burga — a former Peruvian soccer official facing a racketeering conspiracy charge — had been an attempt to intimidate the first witness called to testify in the case.

“There’s probable cause to believe he attempted to tamper with the witness,” Judge Pamela K. Chen, a United States District Court Judge for the Eastern District of New York, said. She was considering whether to lock up Mr. Burga, who has been free on bail.

The judge’s remark prompted an outcry from Mr. Burga’s lawyer, Bruce L. Udolf, who attributed the gestures to a skin condition that made his client’s neck itch. He said that instead of being sent to jail, as prosecutors requested, Mr. Burga needed an urgent visit to a dermatologist.