sentences:  Born in Anaheim, California, Mercer grew up in Snellville, Georgia, where he was a teammate of current NBA player Lou Williams at South Gwinnett High School and with the AAU's Georgia Stars.As a junior at South Gwinnett in 2003–04, he averaged 18.1 points per game and helped the school go 31–2 and win the AAAAA championship.As a senior in 2004–05, Mercer averaged 19.8 points, 8.1 assists and 6.0 rebounds per game, helping South Gwinnett to a 28–3 record and the quarterfinals of the Georgia Class 5A state tournament.