Jeffrey Monakana has been ruled out of the Aberdeen squad for the trip to McDiarmid Park.
The winger, who has come in on loan from Brighton, has not been able to train this week because of a virus and will have to wait for his Dons debut.
Skipper Russell Anderson and Clark Robertson will return to the side after sitting out the 2-0 win at Kilmarnock.
Aberdeen will be looking to avenge the defeat to the Saints in the Scottish Cup semi-final in April.
St Johnstone manager Tommy Wright is able to call on skipper Dave Mackay for the visit of Aberdeen on Saturday.
The defender has succeeded in his bid to overturn his red card from last week’s 3-0 defeat by Celtic and therefore is free to play.
Wright’s hand is further strengthened by the addition of Simon Lappin, the former Scotland U21 international having signed a two-year deal and he goes straight into this weekend’s squad.