Mike Jennings was the son of the 1937 Springbok CB Jennings and like him was educated at Dale College in King William's Town. Like André de Wet he played for Border at the first Craven Week and then went about getting himself qualified as a primary schools teacher first at Graaff-Reinet Teachers' Training College, then at Paarl Training College and then at Wits, in the process playing [provincial rugby for North Eastern Cape, Boland, Western Province, Transvaal and Eastern Transvaal.

He was at Paarl training College and playing for Boland when he became a Springbok in 1969, playing in eight tour matches but no Tests.