Business time for Barcelona

Xavi, Zlatan Ibrahimovic and half the defence are likely to miss tonight's match against VfB Stuttgart.

Barcelona, the European Cup holders, play the in-form German side VfB Stuttgart away tonight in the first leg of their last 16 Champions League tie. The Catalans have not played a midweek game for six weeks and Carles Puyol, their captain, was keen to stress the need for Barca to concentrate.

"We are not at the business end [of the season] just yet, but we're close," he said. "Teams are at a similar level and mistakes prove costly. We have to give everything and defend the cup as champions." Saturday's 4-0 thrashing of Racing Santander lifted the Catalans' confidence after their first league defeat of the season a week earlier against Atletico Madrid. Fans were even treated to a rare Thierry Henry goal, though few expect him to be earning his living in Catalonia next season, with Barcelona keen to get their third highest earner off the wage bill and give their rising stars more minutes.

With Xavi injured, Zlatan Ibrahimovic a doubt for tonight and Barca's defensive shortages still evident, it was a further boost that Andres Iniesta marked his 300th Barca appearance with his first goal since the tie-winning, last-minute strike against Chelsea 10 months ago. Iniesta will be key if Barca are to become the first club since Milan two decades ago to retain the European Cup. "The win was a moral booster ahead of the game in Germany," added Puyol. "We didn't play brilliantly, but it was practical."

Puyol scored against Stuttgart when the two teams met and Barca triumphed in the 2007-08 Champions League, but he considers the Germans are much improved. "They are a dangerous team," said Puyol. "They are playing very well and if we don't go there focused, we could really have a bad time." After finishing third in the Bundesliga last season, Stuttgart had a dreadful start to this term and they were in the relegation positions after a 4-0 thrashing by Bayer Leverkusen in November. Their form has picked up significantly since, with six wins from seven league games including a 3-1 victory over champions Wolfsburg.

They left it late to qualify for the last 16 in second place from a group containing Glasgow Rangers, Sevilla, who topped the table, and Unirea Urziceni, the Germans winning their last two matches - their only victories in six games. Saturday's 5-1 win at Koln was their season's best, with Cacau, their Brazilian striker, scoring four. A Bundesliga champion with Stuttgart in 2007, Cacau acquired a German passport last year and made his German national team debut soon after.

The win lifted Stuttgart to ninth and their coach Christian Gross, formerly of Tottenham, said: "We're looking forward to playing against Barca, the best team in the world. We must gather our forces and if all goes well, maybe we can give them a surprise." Stuttgart have experience and quality. Jens Lehmann, the goalkeeper may be 40, but the former Schalke, Milan, Borussia Dortmund and Arsenal shot stopper remains hugely influential at the club. Lehmann retired from international football after winning 60 caps in 2008 - the year he joined Stuttgart - and has said that this will be his last season. He has previous with Barca having played for Arsenal against the Catalans in the 2006 Champions League final, where he was aggrieved to be sent off after 18 minutes for a professional foul on Samuel Eto'o.

Another Stuttgart player with a point to prove against Barca is midfielder Aleksander Hleb, who is on loan from the Catalan club after a less than spectacular 2008-09 season with Barca in which he felt he did not feature enough and was played out of position. Having started more games than any other Stuttgart player this season, he is in the perfect position to show his masters what they are missing.