Spurs go into their Europa League last-32 second-leg meeting with the French side holding a 2-1 lead courtesy of a Gareth Bale-inspired victory at White Hart Lane.
And, though keeping a clean sheet would prove sufficient for the north London club to progress, Gallas says scoring will be his side's priority.
|SPURS MARCH ON|
|5/2||Tottenham are 5/2 with BetVictor to draw with Lyon and progress to the last-16 of the Europa League|
"If we put them under pressure straight away they will be wary because if they concede a goal, they will be in trouble," he told reporters.
“We don’t have to try to come back to London with a 0-0 scoreline. We have to play our game, the way we play all the time and then I think then we can qualify,” said Gallas.
"If they score and we then fail to score, we’ll be out."