Before playing in the NHL, Brewer played 3 seasons in the Western Hockey League with the Prince George Cougars. He was drafted with the 5th overall pick by the New York Islanders in the 1997 NHL Entry Draft. He made his NHL debut with the Islanders on October 10, 1998 in a game against the Pittsburgh Penguins. He scored his first NHL career goal on November 5, 1998 against Trevor Kidd of the Carolina Hurricanes.