In addition, defensive end Kenyon Coleman was placed on injured reserve.
Breaston and Crayton were brought in as insurance after Joe Morgan, who was ticketed for the third receiver spot, suffered a season-ending injury. But young wide receivers Nick Toon and Kenny Stills have fared well in training camp and the preseason, making the two veterans expendable.
Wallace, who was competing with Luke McCown to back up Drew Brees, completed three of six passes for 32 yards in his five scoreless series of a preseason game against Oakland on Friday night. He also was intercepted and fumbled into the end zone, resulting in an Oakland touchdown.
Coleman tore a pectoral muscle earlier this month. His season is over as he was not designated for possible return.
Information from ESPN.com's Pat Yasinskas and The Associated Press was used in this report.