STUTTGART; Reigning European kings Barcelona travel to Stuttgart on Tuesday for a Champions League last-16 first leg clash that a few months ago looked as if it would be a formality for the Spanish giants.

But with the German side on rampant form of late, winning six of their last seven matches including a 5-1 drubbing of Cologne away on Saturday, the Catalans might find themselves with anything but a walk in the park. “We want to create an upset,” said striker Cacau, who scored four of Stuttgart’s goals on Saturday.

Barca captain Carles Puyol is aware they will have to be

careful. “We know it will not be

easy and if we are not fully concentrated then things will go badly. At this stage mistakes can be very expensive,” said Puyol.

Barca won a historic six trophies last year, including the league, Champions League and Cup treble, and this season they have lost just three games. But their defence of the Champions League title got off to a slow start and in the group stages they were on the ropes after a defeat at home by Russian side Rubin Kazan. They won a crucial home game though against Inter Milan to help them through to next round.

Stuttgart, meanwhile, have had a roller coaster few months to follow up their stellar 2008-9 season when they came within a whisker of winning the Bundesliga, only to lose out in a seat-of-their-pants last day. This season, a 4-0 hammering by Bayer Leverkusen on the first day set the tone, and by late November, Stuttgart had crashed to 17th in the table, with only the hapless Hertha Berlin below them.

But since firing coach Markus Babbel and bringing in the Swiss Christian Gross at the start of December, the worm has turned, with the team rising to ninth in the table.

Also on Tuesday, Bordeaux clash with Olympiakos.