Arsenal may not facing Barca and Munchen in Group stage, but they still will face PSG. PSG Still strong without Ibrahimovic. And it still hard to beat them.
In 1st round Arsenal have fixture with PSG, PSG infield strong side and they have pretty high chance to win this encounter, but on other Arsenal is also had a good run for new season in EPL, so it would be tough encounter and PSG have to play extraordinary to take some advantage.