The longtime Phoenix Mercury star is joining the Atlanta Dream, and discussed her decision in an Unrivaled social media clip.

After 11 seasons in Phoenix, 10-time WNBA All-Star Brittney Griner has agreed to a deal with the Atlanta Dream, sources tell me and @alexaphilippou. Griner spent her entire career with Mercury and now heads to Atlanta in one of most stunning free agency moves in league history. pic.twitter.com/NfdAuYOAVs

Dream star Allisha Gray couldn't contain her excitement after hearing of Brittney Griner signing with Atlanta after spending her entire career with the Phoenix Mercury

Brittney Griner is leaving the Valley for Atlanta. After 11 seasons entirely played with the Phoenix Mercury, the 10-time All-Star center Griner has agreed to join the Atlanta Dream in free agency. ESPN's Shams Charania and Alex Phillipou were first to break the news.

Amid a flurry of trades across the WNBA, the Indiana Fever re-signed All-Star guard Kelsey Mitchell to a one-year supermax contract worth around $249,000. Sometimes an evaluation doesn’t need to be overcomplicated. Fever executives entered this offseason with the top priority of re-signing two-time All-Star Kelsey Mitchell. Mission accomplished.

Griner entered the offseason as the second-longest tenured WNBA player with one team, having spent her entire career in Phoenix.

In a move that shakes up the WNBA, Brittney Griner is joining the Atlanta Dream in free agency after a decorated 11-season stint with the Phoenix Mercury.

WNBA All-Star free agent center Brittney Griner announced she's signing with the Atlanta Dream after spending her entire 11-year career with the Phoenix Mercury in a video shared on her Instagram account Tuesday (January 28).

In Phoenix, the center lived up to her draft potential, won a title and was a fan favorite. What lies ahead in Atlanta?