The Gunners suffered a sobering 5-1 defeat away to Bayern Munich on Wednesday night to leave them bottom of Group F and with qualification to the last 16 now out of their hands.
Robert Lewandowski opened the scoring with a header in the 10th minute before a brace for Thomas Muller and goals from David Alaba and substitute Arjen Robben secured an impressive victory for Bayern.
Olivier Giroud pulled one back for the dumbstruck visitors, who were already four goals down when he buried an acrobatic volley.
Costly defeats to Dynamo Zagreb and Olympiacos before this mauling have left Arsenal with one win from their first four games and perilously close to elimination.
But goalkeeper Cech, whose last appearance at the Allianz Arena saw him lift the Champions League trophy as Chelsea beat Bayern on penalties, reckons everything is still to play for.
"Of course we can still qualify," he said.
"You win two games and we need to make sure the head to head against Olympiacos is in our favour and then we can go through.
"Everything is possible and we have two games to play
We have to regroup and continue fighting until the last minute."
Olympiacos scored a last-gasp winner against Zagreb on Wednesday that means any positive result for the Greek side in Munich in the next round of fixtures would kill off Arsenal's hopes and allow the current top two to advance.
Bayern boss Pep Guardiola has insisted his side will be looking to win the game rather than play out a mutually beneficial draw and Cech is happy to let other results take care of themselves.
"Obviously this was not a day we wanted, but in a way the situation in our group thanks to the result in Greece hasn't changed much," he added.
"We are still in the position where we need to win our last two games and make sure we have a better head to head against Olympiacos."
Arsene Wenger's side have a great chance to bounce back from the defeat in style as they host north London rivals Tottenham on Sunday looking to maintain their impressive league form.
Only goal difference is keeping Arsenal behind leaders Manchester City heading into the derby and Cech knows the players cannot go into that game still thinking about their humbling defeat in Germany.
"Every game comes thick and fast and you have to make sure you recover and move onto the next one," he added.
"In terms of the league, you win, you lose, you have to make sure you are ready for the next game.
"(The defeat to Bayern) is tough to take but in a way you have to accept that the team you played against was superior to us in everything they have done, especially in the first half.
"There are some positives in the second half but obviously we need to do better defensively and be more aggressive because we allowed them too much time on the ball."
Source : PA