Wenger worried Hulk could cause havoc
The Gunners play the Portuguese outfit at the Estadio do Dragao on Wednesday without a host of first-teamers, including Manuel Almunia, Williams Gallas, Kieran Gibbs, Alex Song, Andrei Arshavin, Eduardo and Robin van Persie.
And as well as Colombian forward Radamel Falcao - who has netted 14 goals in 17 league games for the Dragons - the Emirates Stadium outfit will also have to contend with Brazilian powerhouse Hulk.
The Samba star - who made his international debut against England in November - is currently serving a six-month domestic ban after attacking a steward in December, but is available to play in Europe.
Wenger believes that despite his lack of regular action, the former Tokyo Verdy goal-getter will prove more than a handful for his depleted side and could prove the difference between the two teams.
"Hulk is a powerful boy and I know he has been suspended in the Portuguese League for six months," he said.
"But he has tremendous pace and power so we will want to keep him quiet."
The task of keeping Hulk quiet will be left to Thomas Vermaelen - nursing a badly bruised leg - and Sol Campbell following the loss of Gallas through injury.
Campbell has made just two appearances since re-joining the Gunners following a short stint at Notts County, and last played a Champions League game in 2006 - scoring against Barcelona in the final at the Stade de France.
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