The Daily Mail says amid rumours of serious dressing-room unrest, the Stamford Bridge hierarchy are understood to be hugely disappointed with Grant's failure to rise to the occasion at Wembley.
Owner Roman Abramovich visited the Chelsea dressing room after Tottenham's much-deserved 2-1 victory and is said to share the views of those who thought Grant not only picked the wrong team but then displayed a lack of tactical nous and also failed to inspire his players at key times.
In particular, they were shocked to see him on the periphery when coach Steve Clarke delivered a team talk between the end of normal time and the beginning of extra-time.
The Israeli seemed to have the full support of his employers when they handed him a four-year contract in December and he also had their public backing when the club announced their financial results last week.
Chairman Bruce Buck said: "We judge a manager on results and, to date, his results have been very, very good." Before Sunday, his record was impressive. In 34 games since succeeding Jose Mourinho he had won 24 and drawn eight.