The 17-year-old featured in the club's most recent Carabao Cup tie against Bournemouth, putting in an impressive display as the club emerged with a 2-1 win.
However, Chelsea will still have to resolve the matter of how much is owed to Exeter for the transfer. The Exeter Chairman Julian Tagg spoke about the issue recently:
"We don't have a date yet for the tribunal but the arbitration is taking its natural course and we will inform fans when we know more," he said.
"Our relationship with Chelsea remains good, as it has been throughout this whole process, and it is nice to see Ethan doing so well and earning praise for his performances at both club and international level."