The veteran Belgium midfielder has moved to Girona after coming off contract with Atletico Madrid over the summer.
At his presentation today, the veteran said: "When I spoke with Míchel and Quique, I immediately connected and decided that Girona was the right place for me.
"It all happened very quickly, and I realized that the best option for me and my family was here. Role? The coach (Michel) told me he wants me in midfield, it's my favourite position, although I can also play in defense.
"I share many of the same playing styles with coach Michel, such as possession and pressing."
Meanwhile, Girona sports chief Quique Carcel added this morning: "Among other qualities, we appreciate Witsel's experience, his ability to pass balls and put them into the box. He has great playing ability."