Singer explained with Alan Cumming was an ideal choice for the role of Nightcrawler, "Not only is an exceptionally fine actor, but he also has a sense of humor, and I felt the role required not only acting chops, but also a sense of humor and also a strong sense of character."
Chosing to recast the role of Pyro was based on the character's development as well as age range. Singer offers, "Well, because Anna Paquin and Shawn Ashmore who plays Bobby Drake have gotten a bit older, and I wanted somebody a little rougher with a darker edge, and I had seen 'Tadpole' and I thought Aaron Stanford really had the chops as an actor, and also an edge to him."
Singer explains that Daniel Cudmore got the part of Colossus after Singer and producer Lauren Shuler Donner realized they had found someone with fairly uncommon physical attributes, "He also happened to be a 21 year old man who is 6'8''. Which is very unique (laughs). He had also the age of one of Xavier's students, and almost the size of Andre the Giant."
Check out Countingdown.com for the rest of the interview.