The Gunners finished second in Group F following a 2-0 defeat to Napoli in Naples on Tuesday.
"Of course to finish second makes the potential draw more difficult," he told reporters. "In the last four or five years we have had very difficult draws, so maybe this time we will be more lucky.
"But if you look at the teams who are potentially there, at least we know we will have a difficult draw.
"On the other hand, we have now qualified for a 14th consecutive year for the last 16 and maybe number 14 will bring us a bit of luck."
Borussia Dortmund won Group F.