Jamie Rhodie is facing trial over allegations he committed a religiously aggravated breach of the peace on a train from Glasgow to Dundee on September 10 last year.
He was travelling for Rangers' SPL encounter with Dundee United at Tannadice when the alleged incident took place.
Sheriff Harry Small based at Hamilton Sheriff Court is a "key witness" for the prosecution.
Lawyers for Rhodie yesterday told Dundee Sheriff Court they were waiting to view CCTV evidence.
Rhodie, 18, of Gartcosh, denies committing a racially aggravated breach of the peace. Sheriff Tom Hughes continued the case to trial later this month.