Abstract: Techniques are described for handling stale variant cases that arise in adaptive streaming of content by media players. For example, embodiments include a delegate subsystem integrated with a media player client. The delegate subsystem can act as a proxy for requesting variant manifest update requests on behalf of the media player client and for receiving corresponding responses. The delegate subsystem can track the received update responses to determine whether the responses indicate a stale variant condition. If so, the delegate subsystem can issue a failover trigger to the media player client, such as by returning an error code, a variant gap tag, or the like. The failover trigger can cause the media player client 110 automatically to respond by executing a failover routine.