Hayden accepted an athletic scholarship to attend the University of Florida in Gainesville, Florida, where she played for the Florida Gators women's basketball team from 2000 to 2004. As a senior in 2004, she was a first-team All-Southeastern Conference (SEC) selection, SEC Defensive Player of the year, and a second-team All-American. She graduated with a bachelor's degree in 2004.
Following her collegiate career, she was selected 7th overall in the 2004 WNBA draft. As a rookie in 2004, Hayden-Johnson averaged 5.3 points and 2.9 rebounds per game. In 2005, she improved, averaging 7.9 points and 5.3 rebounds per game.
The 2006 season was a struggle for the third-year center. After reporting to the pre-season training camp 20 pounds overweight, Hayden-Johnson lost her starting job early on and remained prone to foul trouble. With her minutes cut, she averaged 5.4 points and 3.5 rebounds per game.
Hayden-Johnson missed the entire 2007 WNBA season to give birth to her first child. She returned to action in 2008 as a reserve for the Lynx. On January 30, 2009, Hayden-Johnson was traded to the Los Angeles Sparks for Christi Thomas.