CAS released a statement on Monday confirming that they had granted Santos "a stay of execution" in the case of his eight-match suspension dating back to an offence at the World Cup, when he was in charge of the Greece national team.
Santos was found guilty of unsporting conduct towards a match official during Greece's round of 16 defeat against Costa Rica in Brazil and was subsequently hit with the ban.
The 60-year-old left his post in the aftermath of their World Cup exit, and was appointed Portugal coach in September following the departure of Paulo Bento.
Santos saw an initial appeal against the sanction rejected, ruling him out of taking his place on the touchline for any competitive fixture for Portugal.
The coach was in the dugout for Saturday's 2-1 friendly defeat to France in Paris, and CAS' statement on Monday means he will be able to do the same against Denmark in Copenhagen, with a final decision expected by the end of next month.
"As a preliminary step, the coach filed a request for a stay of execution of the FIFA decision for the duration of the CAS proceedings," the statement read.
"Having considered the parties’ submissions, the President of the CAS Appeals Arbitration Division has today issued an Order granting Mr Santos’ request.
"Accordingly, Mr Santos is able to perform his coaching duties until the CAS arbitration concludes. In this regard, the parties have agreed to conduct the arbitration on an expedited basis and the CAS expects to be in a position to issue a final decision by the end of November 2014."
