After defeats to Canada and world champions Greece, Britain rounded off their ultra-competitive group campaign against Olympic gold medallists from London 2012 USA.
Britain started slowly, losing the first quarter 4-0, and, despite equalling USA in the second to make it 6-2, their North American counterparts were eventual 16-4 winners in Barcelona.
Next up for Britain are Hungary in the first round of knockout matches on Saturday and Metz wants his players to leave everything in the water with quarter-final places up for grabs,
"We started off 4-0 down but we were able to repair that in the second quarter drawing it 2-2. We swapped a few things but they didn't work out," said Metz.
"The USA were definitely a size too big. We will go into any game to get the result. Winning will be the best result but we respect all teams and we need to play our personal bests on Saturday."