Laudrup is relishing the prospect of facing his former club, with whom as a player in the early 1990s he won four league titles and a European Cup during an era when the side known as the "dream team" dominated Spanish football.
"We have to be realistic. Spanish football is much better than Danish football, Barcelona is much better than Brondby. But in football anything can happen," Laudrup, who made more than 100 appearances for Denmark in an illustrious career, told Reuters before the first leg in Copenhagen.
"Logically there should be a difference. We need some luck and must hope that, maybe, they will be distracted."
Laudrup's optimism has been dampened by Barca's resurgent league form. Five wins in a row have carried Frank Rijkaard's side up to fourth after a slow start to the season with the Catalans, who have not won a trophy since 1999, inspired by the return of Brazilian Ronaldinho from injury.
Barcelona will be without Rafael Marquez and Edgar Davids. Centre-back Marquez is facing up to three weeks out after suffering an injury to his left thigh in Saturday's 1-0 win away to Valencia. Davids, who has been outstanding since his arrival from Juventus in January, is ineligible.
Inter Milan, three-times winners of the competition, must bounce back from Saturday's derby defeat by AC Milan when they travel to Sochaux, who sit fifth in Ligue 1.
Inter led their city rivals 2-0 before losing 3-2 and any hangover is sure to be punished by the French side who thumped Borussia Dortmund 6-2
Former Serie A leaders AS Roma also face a tough away leg at Gaziantepspor, one of four Turkish sides still in the competition.
Under-fire Liverpool boss Gerard Houllier says his side need a good result against Bulgaria's Levski Sofia at Anfield with the pressure mounting on the Frenchman.
The 2001 winners have failed to mount a title challenge this season and lost in the fifth round of the FA Cup at Portsmouth on Sunday.
"It's a big game in our season and the players are aware of that," Houllier told the club's website.
"The good thing about when you lose is that there's always another game for you to try and put things right."
Last season's beaten finalists Celtic set a British record of 24 successive wins on Sunday but will be wary of the threat posed by giantkillers Teplice who they host at Parkhead.
The side from the north of the Czech Republic have already beaten 2002 winners Feyenoord and Germany's Kaiserslautern and coach Frantisek Straka said the trip holds no fears.
"We know all about Celtic and their qualities. We respect them but we are not frightened. If we were frightened, there would be no point in us going to Scotland," Straka told a Scottish newspaper this week.