Bayer Leverkusen's South Korea striker Son Heung-Min says his team must forget their stumble in Stuttgart when they host Zenit St Petersburg in the Champions League on Wednesday.

Son scored two goals in the opening nine minutes at Stuttgart on Saturday as his side finished 3-0 up at half-time, only to concede three goals and throw away two valuable league points.

There is all to play for against the Russians at the BayArena with just a point separating joint Group C leaders Zenit, who are level with Monaco, and third-placed Leverkusen.

Having lost their opening European match 1-0 at Monaco, Leverkusen bounced back with a 3-1 win at home to Benfica on October 1 with Son, Stefan Kiessling and Hakan Calhanoglu getting on the scoresheet.

Son says Bayer must concentrate on the positives from their Benfica win and forget the second-half in Stuttgart when they run out against Zenit.

"We need to play with the same confidence we showed against Benfica, take the positives from that and analyse what went wrong against Stuttgart," said Son, who was only denied a hat-trick by the crossbar in Stuttgart.

Former Chelsea manager Andre Villas-Boas has said his Zenit St Petersburg side need to be wary of their trip to Leverkusen despite their strong recent record in Germany.

Zenit's 2-1 win at Borussia Dortmund in last season's round of 16 was their third victory in their last five visits to Germany, but a 4-2 home defeat against Dortmund in the first-leg meant they exited the competition on aggregate.

"Leverkusen are a very, very good team who will require a lot of us," Villa-Boas told SID, an AFP subsidiary, in a conference call.

The 37-year-old says his team will need a disciplined performance against Roger Schmidt's side to take anything from Leverkusen as they look to defend their status at the top of the group.

"That's obviously our goal, then we'll be in a really good position after three games," said Villas-Boas.

In Leverkusen, the Zenit coach will have the services of Belgian international Axel Witsel who played 25 minutes of their Russian Premier League draw with FK Krasnodar after an ankle injury.

"I am fully fit again, said the 25-year-old, who said Zenit need to watch out for Leverkusen's potent strike-force including Son and Germany's Karim Bellarabi.

"If we produce our best performance, we'll be able to hold our own in Leverkusen."