Police said one fan was arrested following an allegation of a racially motivated public order offence ahead of tonight's Europa League cup game.
However reports of a Wolves fan being stabbed are not true, West Midlands Police said, with Chief Constable David Thompson describing the Slovakian fans as "very good natured".
It comes after reports of trouble at the Red Wings Lodge, near Molineux, on Wednesday night when a flare was allegedly set off inside the building.
Wolves won the away fixture in Slovakia 2-1 last month "behind closed doors" under a Uefa sanction for racism from Bratislava fans, although more than 20,000 fans were inside the ground after under-14s were allowed in for free with one adult for every 10 children.
Some 1,000 away fans are said to have travelled over for the match at Molineux, with 400 not having tickets for the game which Wolves won 1-0/
West Midlands Police Force Support Unit tweeted: "Slovan Bratislava fan arrested in Wolverhampton following a report of a racially motivated public order offence.
"We think he'll miss the match and possibly his flight home. #EnoughIsEnough".