Van den Berg that incidentally means "from the mountains" in Afrikaans was born in Observatory, a suburb of Cape Town and was skilful in many sports. Before arriving at Liverpool in October 1937 he had been prominent at football, cricket and rugby, even capped for Western province, the South African Rugby Union team. As soon as he stepped off the Union Castle liner, Carnarvon Castle, from Capetown, on 18 October 1937, George Kay, was there to meet the South African in Southampton and obtain his signature on a professional contract. Van den Berg played on the left wing at Liverpool and made his first-team debut in the Goodison derby on 16 February 1938 replacing the injured Alf Hanson, joining fellow South Africans Arthur Riley and Berry Nieuwenhuys in the first eleven. Liverpool beat Everton 3-1 and the Daily Post concluded: "One would have thought van den Berg had been playing in senior football for years instead of making his debut." The Liverpool Echo also had plenty of praise for the 19-year-old: "nicely built, speedy, good ball control, accurate with his centres, and a good shot, he made a most encouraging debut." Hanson returned after an absence of three games and van den Berg didn't add to his total until he made 12 consecutive appearances in the first half of the following season before succumbing to a serious cartilage injury that kept him out until four weeks were left of the campaign.

Van den Berg was in the team when the 1939/40 season started but the outbreak of war meant that league football was suspended, although the club did continue to play in the quickly-arranged Western Division and War League Cup. Of the three league goals that Van den Berg scored for Liverpool, two were particularly dramatic - an equaliser in the last minute to save a point at Leicester in October 1938 and a first-minute strike in the 3-3 Anfield draw with Huddersfield Town three weeks later.