Gunnell is the only woman to have held the European, World, Commonwealth and Olympic 400 metre hurdles title at the same time.
Sally won two Commonwealth golds and a silver in 1990 - she also won gold for the hurdles in 1994.
Her greatest victory came at the 1992 Olympic Games in Barcelona when as captain of the British women's team, winning a gold medal for the hurdles and a bronze for the relay.
Sally feels that home advantage could lead to a huge medal haul at the Games.
She is tipping the likes of Mark Lewis-Francis, Julie Holman, Catherine Murphy and Chris Tomlinson to shine in Manchester.