Nix, 29, had his contract purchased from Triple-A and was added to the Yankees' roster on Thursday. In a corresponding move, Eric Chavez was placed on the seven-day disabled list with a concussion.
"I wouldn't say I was expecting it, but I also know that you never know in this game," said Nix, who found out about his promotion late on Wednesday and had to change planes in Chicago. "Anything can happen any day, so I wasn't surprised."
Nix had played eight games at Triple-A after attending Yankees Spring Training as a non-roster invitee, batting .233 (7-for-30) with five runs scored, four doubles and four RBIs. He had played left field once at Triple-A this year.
"I feel comfortable. I don't have a whole lot of games of experience," Nix said. "But every time I've been out there I've been comfortable and had no problems."
Chavez did not travel with the Yankees to Kansas City and was said to be resting comfortably at home after being checked out at a New York hospital on Wednesday. Manager Joe Girardi spoke to Chavez on Thursday and said it was too soon to know if Chavez could return in the minimum seven days.
"He was pretty good," Girardi said. "He said he felt like he had been in an accident a little bit. He was sore a little bit. He was much clearer than when I saw him last night."