The Danish side dropped into the Europa League after two impressive performances in the qualifying play-offs for the Champions League.
An astonishing 4-3 win in Greece saw them past Panathinaikos and they then beat Spanish side Villarreal 1-0 in the first leg of their tie before being overturned 3-0 in Spain.
While those encouraging performances would suggest Odense have a good chance of coming away with a positive result at Stadion Miejski, Clausen knows his squad cannot afford to underestimate the Polish champions, who have lost just one of their last 10 European home games.
He told the Odense website: "Wisla Krakow is a fantastic team. I am not sure that too many people have heard so much about them, they are an excellent team and one of the best teams in the Polish league.
"They have just defeated Lech Poznan at the weekend, who beat Juventus and played straight up with Manchester City, so it's a team at a high level.
"They have a Dutch coach (Robert Maaskant), players and a Dutch-inspired 4-3-3 system with some really good offensive players.
"Wisla Krakow are not the highest-profile team in Europe, but that does not mean that the task becomes easier.
"It might just make the task harder. There were not so many who had heard of Rubin Kazan a few years ago but they are still a strong team and it makes this a difficult task."
Clausen has new signing Djiby Fall available after he was granted a work permit but Jacob Schoop and Kalilou Traoré are injured while Bashkim Kadrii is suspended.
Wisla, meanwhile, will be looking to build on their win over Poznan, which lifted morale after a difficult start to the league season that sees them sitting ninth in the table after six games.