Chandler sprained his left ankle on Monday in the Hornets' victory over Indiana. Armstrong also left that game with left knee soreness and neither were able to play on Wednesday night against the New Jersey Nets.
David West, who missed the game against Indiana with back spasms, also sat out against the Nets.
Tolliver, who is 6 feet 8, is in his third season out of Creighton, having spent most of his career in the minor leagues. His NBA experience consists of 19 games with the San Antonio Spurs last season, averaging 2.7 points and 2.2 rebounds in about 11 minutes a game.
Hornets coach Byron Scott said he did not expect Tolliver to play against New Jersey because he didn't know New Orleans' plays.
Chandler, who averages 8.8 points and 8.3 rebounds, is listed day to day but Scott said he could be out more than a week. The status of Armstrong, Chandler's primary backup, is less certain. He is expected to have a precautionary MRI on Thursday to ensure there is no structural damage to his knee.
"He's never had a knee problem so more than anything it's probably scaring him," Scott said.
West, Chandler and Armstrong all are expected to miss New Orleans' game at Minnesota on Friday night, but Scott is hopeful West could return when the Hornets host Philadelphia on Monday.