The Gunners were beaten 1-0 at Stoke on Saturday. The result saw them fall to third in the table, level on points with second-placed Liverpool and four adrift of Chelsea, who beat Fulham.
Asked how difficult it will be to close the gap between them and Chelsea, Wenger said:
We cannot say it's easy. It is difficult, but I expected them to win at Fulham.
The Frenchman also defended criticism of his team dipping in form towards the end of campaigns:
I would say look at our results at the crucial point in the season and you would be surprised. Somebody says something that is not checked and everyone repeats it and it becomes an opinion, even if the facts don't show it. Our end of season has always been very strong.