Salukis host Upper Iowa at 7:05 p.m. Saturday.
Jalen Pendleton and Anthony Beane, Jr. have signed scholarship agreements with SIU.
Head coach Barry Hinson will introduce his coaching staff.
McGee has served the past two seasons as an assistant coach at Grand Valley State University.
Saluki men's basketball coach Barry Hinson named Terrance McGee, one of his former players at Missouri State, to his staff at Southern Illinois University on April 19, 2012.
McGee served the previous two seasons as an assistant coach at Grand Valley State University, during which time the Lakers compiled a 33-21 record, including a 19-8 mark and third-place finish in the Great Lakes Intercollegiate Athletic Conference in 2011.
"It is imperative that we find somebody who has energy, is loyal and really wants to work hard," Hinson said. "Terrance met every one of these criteria as both a player and as an assistant coach, and I am more than happy to bring him on board. He is fired up about becoming a Saluki."
A 6-foot-2 guard who played collegiately for two seasons at Missouri State (2001-03), McGee averaged 14.9 points, 3.5 rebounds and 4.3 assists his senior year and earned First-Team All-Missouri Valley Conference and All-Defensive Team honors. Prior to MSU, he spent two years at Kirkwood Community College (1999-2001). After his college career, McGee played professionally overseas for seven years.
"Terrance is real up-and-coming star in college coaching," said Ric Wesley, head coach at GVSU. "Our players have great respect for him because of his wealth of playing experience. He's a high-energy guy who has been a part of everything we do in our program."
A native of Milwaukee, Wis., McGee earned his undergraduate degree in hospitality and restaurant administration at MSU and was working toward a master's degree at Grand Valley.
"Coach Wesley got my feet wet in recruiting, breaking down film, scouting reports, and I got a taste of the Division II world," McGee said. "I'm ready to take the step to Division I and work for Coach Hinson, who has been a mentor and a father figure for me."