Sport News Update, what you need to know

AFL - Prized West Coast recruit Lewis Jetta is in doubt for the start of the AFL season after injuring his calf muscle in Thursday's three-point AFL pre-season cup win over Gold Coast in Joondalup.

TENNIS - Sam Groth is ready to fight fire with fire when he steps in for an ailing Nick Kyrgios to take on fellow big-server John Isner on the opening day of Australia's Davis Cup tie against the US.

GOLF - Adam Scott picked up where he left off in winning last week's Honda Classic, moving within four shots of the lead midway through his opening round at the World Golf Championships, Cadillac Championship at Trump National Doral.

CYCLING - Australia will ride for gold in the men's team pursuit after dismantling defending world champions New Zealand in the semi-finals at the track cycling world championships in London.