The 25-year-old is eager to come face-to-face with his old friend when they meet on the field this weekend.
He told reporters: "It's definitely a good opportunity for us to be able to play against guys that, at the club level, we've played against and played with. Leon Goretzka, for instance, was like a big brother to me when I was coming through the ranks at Schalke, so it's going to be nice to be able to see him and play against him as well and maybe be able to say some bad words to him in German, just to refresh my memory of how it used to be."