Olympiacos coach Leonardo Jardim has promised his team will give Arsene Wenger's Arsenal a tough time in Athens in a fortnight when the Gunners travel to Greece to try to win UEFA Champions League Group B.
Olympiacos lost 1-0 at Schalke on Wednesday as Austria left-back Christian Fuchs fired home the thunderbolt winner on 77 minutes which put the Royal Blues into the knock-out phase and kept them top of the table.
Schalke top Group B by a point from the Gunners ahead of the Royal Blues' final game at Montpellier in a week, while Arsene Wenger's side must win in Greece on 4 December to stand a chance of finishing top.
"We didn't achieve our first goal of qualifying, but at least we are in the Europa League now," said Olympiacos' Portuguese coach Jardim.
"We need to put in a good display in our final game against Arsenal in front of our home fans to leave a good impression. We will not make it easy."
Arsenal threatened to usurp Schalke at the top of the group with a 2-0 win in London over Montpellier until Fuchs launched his rocket of a shot to claim his first Champions League goal.
Schalke coach Huub Stevens said he was pleased his side got through, but was unimpressed with his team's display.
"When you reach the knock-out stage before the last group game, you have to be satisfied," said Stevens. "The team produced a characteristically strong performance.
"We can't really be happy with the way we played, but for the club it was vital to reach the knock-out phase for financial reasons. I wouldn't mind if we go on to win the group."
Schalke deserved the win having battered the Olympiacos goal with 27 attempts, 17 on target, compared to the Greeks' six shots as the visitors' goalkeeper Roy Carroll had a busy night.
"We were all quite tense ahead of the game," admitted Schalke midfielder Roman Neustaedter.
"I did not really sleep that well either. We are all extremely happy to have reached the next round."
Olympiacos came to Germany in buoyant mood with seven wins in an eight-game unbeaten run, but they had no answers at the Veltins Arena.
"It was tough work today but we deserved to win as we clearly dominated the opposition," said Schalke captain Benedikt Hoewedes.
"We had a few opportunities and fortunately we managed to score one of them."