Powell will begin next season sitting in the stands after he was charged with misconduct following the recent 2-2 draw with Bristol Rovers.
The 41-year-old was sent off by referee Rob Lewis after going onto the pitch to protest when Gavin Williams appeared to handle the ball before tucking away Rovers' late equaliser.
Afterwards, Powell said: "He just said I've got to go off.
"Obviously I came onto the pitch and explained that it looked like handball."
Source: PA
Source: PA