Robert Lewandowski has warned his Borussia Dortmund teammates nothing is decided ahead of Wednesday's Champions League clash at home to Zenit St Petersburg despite their 4-2 first leg advantage.
The Poland striker scored twice in their last-16 opening match in Saint Petersburg three weeks ago, which puts them on the verge of a place in Friday's quarter-final draw in Nyon, Switzerland.
Dortmund crashed to a shock 2-1 defeat at home to Borussia Moenchengladbach on Saturday and Lewandowski has warned his side they can ill afford a similar performance against Zenit at Borussia's Westfalenstadion.
"We are not through yet, nothing has been decided and if we play like we did against Gladbach then we must be careful," said Lewandowski, Dortmund's top-scorer in Europe with 18 Champions League goals, but who will join rivals Bayern Munich at the end of the season.
The Poland hot-shot already has six goals this season and became the first player to score four times in a Champions League semi-final last April against Real Madrid.
Dortmund will be without Germany winger Marco Reus, who scored in the first-leg and missed training on Tuesday as he struggles to get over a leg injury.
Borussia welcome back playmaker Henrikh Mkhitaryan, who missed the Moenchengladbach defeat with suspension, while Germany centre-back Mats Hummels is looking for a run of form having struggled with injury this season.
A pinched nerve, back injury, ankle problem and a foot injury have seen the 25-year-old miss a total of three months this season.
Dortmund have won only four of their 11 games without him, conceding 16 goals in the process, but have lost only three times with him in the team.
"If Mats plays then it has a positive effect on the rest of the team," said Dortmund's director of sport Michael Zorc.
With a pass completion rate of 83 percent and 70 passes per game, Hummels brings some security to Dortmund's back-four which has been repeatedly hit by injuries this season with his centre-back Neven Subotic missing since November with a knee injury.
"There is no professional footballer, who has managed to play 15 years at a high level without injury," said Hummels.
"Injuries are part and parcel of it.
"During the time you learn to deal with it better.
"The good thing is that at least you get back you motivation and desire, which are at 100 percent."