The 23-year-old actress is rumored to be secretly engaged to Ukrainian boxer Wladimir Klitschko.
According to reports, the star sported a diamond ring on her finger during the weekend.
The Nashville star recently turned heads in a purple bikini on the Florida beaches, but it was the presence of a ring that caught even more attention.
The gem has led to speculation about an upcoming wedding.
In addition, a friend posted a picture on Instagram showing Hayden hugged wrapping her legs around her sporty boyfriend and also flashing a sparkler on her finger.
Separated in May 2011 after a two-year relationship, the couple were first seen together in January.