Having also missed out on Euro 2016, Reus is determined to make sure he is available to play in this year's event - provided he is recalled by national coach Joachim Low.
The 28-year-old only recently returned from a serious knee injury suffered last May, but has scored three goals in as many league games for Dortmund.
"I'll look forward to [the World Cup] when we get there," Reus said in an interview with the Bundesliga's official website.
"My excitement will grow more and more as we get closer and start playing international games.
"We will see what decisions the head coach makes - I'm very relaxed though. I will not miss out through injury."
Reus revealed he has always remained in "close contact" with Low, who will announce a preliminary squad on May 15.
"We stay in regular contact of course, particularly because of my injury," he added.
"We message each other and speak on the phone to discuss my progress and other matters. We're in close contact."
While his short-term future is focussed on finishing the season strongly and, hopefully, making it to the World Cup, Reus admits his latest lengthy absence gave him time to reflect on his future after football.
"I think it's very important that you don't start thinking about your life after football when you are 33 or 34," the former Borussia Monchengladbach player said.
"There are many more amazing things in this world and it's important to think about these things before you retire.
"It's difficult for every single player in my opinion because there is such a big hole to fill. The level of fame is no longer there and people are much less interested in you.
"That's actually a good thing because it allows you to do those things that you perhaps were not able to before. I think it's important to be thinking about your personal life and your family not just when you've retired but also during your career."