The team that finishes fourth in the Premiership will enter next season's Europa League, after Aberdeen and Celtic reached the Scottish Cup final.
The eventual cup winners would have been in the Europa League qualifiers.
But league winners Celtic and the Dons, who are currently second, have already secured European qualification through the Premiership.
Rangers are third, with St Johnstone fourth but Hearts and Partick Thistle can still finish in the top four.
There are five rounds of league fixtures remaining, with the first of those taking place across 28 and 29 April.
Celtic, who beat Rangers in Sunday's Scottish Cup semi-final, will enter next season's Champions League qualifiers with three Scottish sides starting their European campaigns in the Europa League qualifiers. Aberdeen defeated holders Hibernian in Saturday's cup last-four tie.