The Maple Leafs assigned Pickard to the American Hockey League's Toronto Marlies.
Pickard, 25, was 15-31-2 with a 2.98 goals-against average in 50 games last season for Colorado. He was selected by the Golden Knights in the expansion draft but was waived Thursday, two days after Vegas claimed goalie Malcolm Subban off waivers from the Boston Bruins.
Lindberg, 22, has two assists in six career NHL games. He had six goals and 10 assists in 44 games for the Marlies last season. Vegas assigned the Swede to the AHL's Chicago Wolves.