Malaysia slumped to their all-time lowest spot in the FIFA world rankings at 174, while archrivals Singapore remain unchanged at 148.
Ong Kim Swee's team managed to move up to 166 from 171 in the March rankings but a 2-0 defeat in their final World Cup qualifier to Saudi Arabia, along with the goalless draw against Macau brought them crashing down the standings.
Malaysia will have to wait till the 2019 Asian Cup playoff against Timor-Leste in June for a chance to make amends, with the home and away tie scheduled for June 2 and 7.
They subsequently travel to the Oceania region for a series of friendlies against Papua New Guinea (June 17), New Caledonia (June 22) and Fiji (June 26).
"While it is disappointing to see our ranking fall so low, we have an opportunity to move back up when we play a friendly match at the end of May and the two playoff matches against Timor Leste," Ong told the New Straits Times.
"These are very important matches for us, not only for the ranking, but also for our chances to qualify for the Asian Cup. So we cannot afford anymore hiccups from here on."
While Malaysia continue to rebuild the national team under the guidance of Ong, their Causeway neighbours Singapore are searching for a replacement for German coach Bernd Stange.
The former Belarus manager will not be renewing his contract with the Lions and is scheduled to leave Singapore on April 15.
ESPN FC understands that Tampines head coach V. Sundramoorthy will be handed the reins while the Football Association of Singapore goes in search of a foreign coach to take the position on a permanent basis.