The red card issue actually destabilized the entire game plan for Chelsea, from the replay of that tackle, and if it were to be some referee they might have considered that tackle as not a red card offense but should have been decided as a yellow card offense rather
Well, many may not agree but Chelsea performances this season under Pochetinno has not been awful; instead the results have been terrible because there are no one at the end of the chances created to score a score; also with many injuries, Chelsea have had to rely only on Raheem Sterling to create chances and also score goals.
With players returning from injury; i think Pochetino can begin to get the desired results. Chelsea has no choice than to back their manager at this point.