Stadionclub finished second in the Dutch Eredivisie in 2011-12, and could have been drawn against Romanian club Vaslui or Scottish outfit Motherwell, among others.
Coach Yuri Syomin has strengthened the Ukrainain capital club with the likes of Niko Kranjcar, Marco Ruben and Miguel Veloso over the summer, and Koeman is wary of their new-look side.
"It's a tough draw. Dynamo Kiev were not my preference. They have a couple of new players, including some players who were also at the Euros for Ukraine," he told RTV Rijnmond.
"They are a team with experience in Europe and a team that is always competing for a place in the Champions League. Therefore, it's a very difficult draw."
Koeman is confident, however, that his side's preparations for the tie will be aided by the fact that their opponents are already playing league football.
"Kiev have already started their national competition, that may be an advantage to us," he continued. "We have two weekends to watch their games.
"I don't know if we can compete against them, I'm curious about that. I always see chances for our team, no matter who we play."The De Kuip club finished runners-up to Ajax last season, while Dynamo finished four points behind champions Shakhtar Donestk.