Tom Glick has mixed emotions leaving Derby County for the Manchester City chief executive's job.
Glick becomes chief commercial and operating officer at City in August.
The American told BBC Radio Derby: "It is very exciting. It's a chance to be working at the top end of global sport.
"But it's also bittersweet because I know what Derby County are about to do and, not only that, it's been an unbelievably positive journey for me."
Glick said his four-and-a-half-year spell with the Rams had been an "an unbelievably positive experience".