Sol Campbell makes a point during Arsenal’s practice session on Tuesday

London: A string of absentees led by striker Thierry Henry and the fallout from their latest domestic defeat will haunt Arsenal in Wednesday’s Champions League opener against Swiss outsiders Thun.

Henry is out for at least a month with a groin injury, keeper Jens Lehmann is suspended and defender Sol Campbell is a doubt after a lengthy injury lay-off and his absence from Saturday’s 1-2 defeat at Middlesbrough.

That loss followed two others to Chelsea, in the Community Shield and Premier League, in a faltering start to the season by an Arsenal side who look none too solid at the back.

Add the fact that manager Arsene Wenger has not replaced their hugely influential captain Patrick Vieira, now at Juventus, and Wednesday’s Group B tie suddenly starts to look like a banana skin for the once all-conquering side.

Defender Ashley Cole is taking nothing for granted against a club who were playing amateur football less than 10 years ago and whose annual budget is a paltry $4.4 million.

“Wednesday looks like a good game for us to bounce back on paper, but it’s not about the names on paper, it’s about how you play on the day,” Cole told reporters after the Boro defeat.

“They will have nothing to lose and they will come out and try to win. It’s going to be tough for us, but we’ve got to forget about this result and start playing our best football.

“We’ve responded to big setbacks in the past and we’re going to have to do that again if we want to win anything this year.”

Arsenal have never shown their true potential in the Champions League, with only quarter final places to show for their efforts in Europe, despite winning seven Premier League and FA Cup titles under Wenger.

Jose Antonio Reyes and Dennis Bergkamp are likely to lead the attack in Henry’s absence, with Robin van Persie tipped for a second-half appearance.

Campbell may be pressed into action though he is not match fit, having not played a competitive game since last May.

Thun will probably play with the lone striker system that undid Dynamo Kiev and Malmo in the qualifying rounds, with newly-capped Swiss international Mauro Lustrinelli looking to pounce on whatever chances come Thun’s way.

Meanwhile, Werder Bremen are pinning their hopes of a Champions League upset against Barcelona on the golden boots of substitute striker Nelson Valdez.

Bremen coach Thomas Schaaf will be unable to field his first choice attacking line-up in Wednesday’s opening Group C clash with the Catalans, with Germany international Miroslav Klose suspended.

That leaves Valdez to partner Ivan Klasnic up front and the Paraguayan has ordered a new pair of golden boots for the game, identical to those he wore when scoring twice against Valencia to send Bremen through to the knock-out stage last season.

“It’s a big chance for me,” said Valdez, who has been preparing for the opportunity ever since Klose was sent off in the 3-0 win over FC Basel in the qualifying round. The loss of Klose is a big blow for Bremen, who are desperate to restore a reputation that was destroyed in a 2-10 aggregate defeat by Olympique Lyon last season. (Reuters)