United helped supporters, who were injured when a group of locals targeted a bar where fans had gathered in the center of the Polish city.
Videos on social media showed around 30 people dressed in dark clothes – believed to be supporters of Lechia Gdansk, whose Stadion Miejski will host tonight’s game.
The footage showed these fans attacking the bar’s outdoor patio and leaving a trail of damage behind.
In a statement, United said: “Club staff assisted a number of United fans in Gdansk last night. [Tuesday] and today after an incident where some of our supporters were attacked outside a bar in town.
Around 2,000 United supporters are expected to attend Wednesday night’s final against Villarreal, with half of that coming in on match day on official club trips.
Ole Gunnar Solskjaer hopes to win his first trophy as United manager in Gdansk and believes that Europa League success can serve as a “springboard” for his team.
“These are great nights for us. It could be the springboard for something better to come, a bright future because this team is a young team, ”he said in his pre-match press conference.
“It’s a team we’ve rebuilt over the past two years so hopefully this is the start of something more. “
The mayor of Gdansk, Aleksandra Dulkiewicz, condemned the attacks.
He said: “Yesterday there was a rogue attack on the fans of the teams that came to the Europa League final. In Gdansk, an open and united city, there is no room for violence.
“Dear fans and guests, you are always welcome and we welcome you to our city! “