Mandla was born in Phalaborwa and schooled at the Nkateko and Prosperitus high schools, Mashimbyi was chosen for the SA Country Districts Schools team in 1998 and then joined the Northerns Academy.

An energetic pace bowler, who bowled a heavy ball, as well as a useful lower-order batsman, Mashimbyi played for the Titans and Northerns from 2005/06, taking 103 wickets in 39 first-class matches while based at Centurion, and averaging over 20 with the bat.