There seems to be a bit of a rivalry between Friends alumnus Jennifer Aniston and wild child Miley Cyrus.

It has come to RadarOnline's attention that Jennifer Aniston is upset that her longtime hairstylist Chris McMillan has been focusing too much on Miley Cyrus' hairdo.

McMillan was the genius behind Aniston's 1990's Friends "The Rachel hair" and recently Chris gave Miley her sexy blond pixie cut that has given Miley a whole lot of media attention.

Apparently, Justin Theroux's fiancé is upset with all the focus Miley's been getting for her hairstyles and is of the opinion that she's being sidelined when it comes to the priorities of McMillan.

A source has been quoted, "Miley has radically remade her look with the help of handpicked hairdresser Chris, but the successful creative collaboration between the pair is headed for splitsville because of Jen."

Allegedly, Jennifer, 44, is sick and tired of the constant attention that Chris has been giving the 21-year old Miley. Jennifer wants Chris to concentrate on her image this year, especially with all the projects Jennifer has lined up.

"Jen wants Chris to lay off Miley for a while. It's become an ultimatum. She has been dissatisfied with the situation for a long time, and things seem to have reached a breaking point."

Chris has been working with Jennifer for over 20 years. According to Hollywoodlife.com, Jen and Chris are business partners for the brand Living Proof with Jen being the co-owner and Chris handling all the celebrity hairstyling.

McMillian's other Hollywood clients include Michelle Williams, Sarah Jessica Parker, Anne Hathaway as well as Reese Witherspoon and Taylor Swift, to name a few.

During an interview on The Kyle and Jackie O Show, Jennifer said that if given a choice between getting the iconic layered "Rachel Haircut" or shaving her head, she'd choose to go bald.