Jason Richardson, who went to two Final Fours and won a national championship at Michigan State, retired Tuesday after a 13-year NBA career.

Richardson, 34, signed with the Hawks in August but decided to retire on the eve of training camp.

"Today is a bittersweet moment for me. I'm officially announcing my retirement from pro basketball," Richardson wrote on his Twitter and Instagram pages.

On Instagram, he included pictures of him with the five NBA teams he played for — Golden State, Charlotte, Phoenix, Orlando and Philadelphia. Richardson averaged 18 points and 5.2 rebounds in his career.

He was a freshman on the 2000 Michigan State title team and was a second-team All-American the following season, when the Spartans went to the Final Four. Before that he starred at Saginaw Arthur Hill.

He has been hampered in recent years by knee injuries.