The Super Eagles duo were not listed in in the 26-man squad for the tour which was released by Jose Mourinho on Monday.
Anglo-Nigerian youngster Dominic Solanke was however named in the squad along with the newly-signed trio of Cesc Fabregas , Diego Costa and Filipe Luis.
The future of both players at the club has been in doubt in recent times.
Moses was farmed out on loan to Liverpool last season, but following an unsuccessful spell with the Reds and multiplicity of options at Stamford Bridge, his future currently hangs in the balance.
Mikel on the other hand, has been unsettled at the club since the turn of the year having lost his place in the team to Nemanja Matic.
The 27-year-old has already been told to look for new employers, with the club agreeing to lower their asking price.