As well as scoring a goal at the weekend, Costa Rica international Joel Campbell worked tirelessly to help Arsenal to all three points against Sunderland.

The opening goal was Campbell’s second for Arsenal in his 11th appearance of the campaign, and he is set to continue on the wing in the absence of Alexis Sánchez.

“[The win over Sunderland] was a good result for the team,” the goalscorer said. “We got the result and that’s what we wanted. Now we have to prepare mentally and physically for Wednesday’s game because it will be very difficult.”

Campbell came off the bench when Arsenal lost 3-2 to Olympiacos back in September, but he is set to start this time around.

The 23-year-old spent the 2013/14 season on loan at Olympiacos, scoring a Champions League goal against Manchester United in Greece. Now he has to return but will hope to help Arsenal manage the two-goal win which is probably going to be required on Wednesday evening.

“We already played against Olympiacos at Emirates Stadium. They are a great team, a great rival and especially because they play at home,” Campbell added. “In the Pireo (Karaiskakis Stadium) it is very difficult to get points but it is the last game of the group stage and we will give our best.

“It is the most important game of the season so far. It will be a cup final and we have to win to continue in the Champions League.”

Arsenal must win 2-0 or win and score at least three times in order to qualify for the knockout stages of the Champions League once again.

With Alexis out and English duo Theo Walcott and Alex Oxlade-Chamberlain barely back to full fitness, Campbell is expected to start once more and will hope to add to his Arsenal ally of two goals.

Scoring 11 times for the Greek giants during his spell there, Campbell knows exactly how difficult Arsenal’s task is. Hopefully a 12th goal in front of the Olympiacos fans would be enough to help send Arsenal through.