Andre Santos has underlined the importance of Arsenal finishing top of their UEFA Champions League group, but is expecting a difficult test against Schalke.
Arsenal followed up an away win over Montpellier in their opening group game by labouring to a 3-1 home success over Olympiacos earlier this month.
The Gunners will be on the brink of the knockout phase if they beat Schalke on Wednesday, but Santos is wary of the threat posed by the Bundesliga side.
"Of course a win on Wednesday would put us in a strong position, but qualification will also depend on other results," Santos told Arsenal Player. "Obviously to have nine points in three games will be a big step up, but we have to be cautious.
"We know that we have strong teams in our group and there will still be three games after this one, but a win on Wednesday will put us in a good position.
"It is very important to finish the group stage in first place, we now have six points and we will push to finish top of the group.
"Matches in the Champions League are never easy - you play against world-class players and you need to show character and strength at all times.
"Look at our match in Montpellier - we went 1-0 down and we had to fight to get back into the game, which we did very well and won the match.
"We have another difficult match against Schalke coming up, but I believe Arsenal has the quality and I think we will grow game after game in the competition."