Van der Vaart was the inspiration behind Hamburg's run to third place in the Bundesliga last season.

He suffered a serious thigh injury in August and has been sorely missed as Hamburg have lost all three of their matches in Group G to date.

The last of those, a 4-1 defeat away to Porto, pretty much ended Hamburg hopes of making the last 16 of the Champions League.

They are not mathematically out of it, but realistically their best hope would appear to be third place and a spot in the UEFA Cup.

"The target is to finish second in the group or at least third," Hamburg's Peruvian international striker Paolo Guerrero said. "It's going to be tough but we'll give it everything."

Since Van der Vaart returned to the team, Hamburg have managed a win and a draw to move out of the bottom three in the Bundesliga.

Another win on Wednesday would take them to within a point of third place with two games to play.

For Porto, the target will be another victory to take them up to seven points from four games and put pressure on top two CSKA Moscow and Arsenal, who meet in London.