The young American will play this season on-loan in the Eredivisie, having joined in the final week of the summer market.
"But I knew for a long time that clubs were in the picture," Miazga told Der Gelderlander. "Vitesse was also for a long time on the list. I never worried.
"It's a nice club, good staff, beautiful complex, strong competition and a good group of players.
"I'm ready for everything. I've been playing matches at Chelsea in preseason. Fitness is not a problem."