Between August 1 and the end of the season , a trade that involves one or more players who are on a team 's 40 - man roster can not be made .
Waivers are obtained on all such players .
Between August 1 and the end of the season , a trade that involves one or more players who are on a team 's 40 - man roster can not be made unless waivers are obtained on all such players .