St Johnstone have lost their appeal against the bookings shown to Graham Cummins and Chris Kane for simulation during Saturday's 1-0 win over Hearts.
The Scottish Football Association's disciplinary tribunal upheld the decisions by match referee John Beaton.
Saints had submitted their reasons as to why they thought the players have been "wrongly cautioned".
The cards came after Saints boss Tommy Wright had suggested Hearts players were guilty of going down too easily.
Cummins was booked after 15 minutes at McDiarmid Park, but the Irishman went on to score the only goal of the game 12 minutes after half-time.
He was replaced by Kane late in the match and the substitute was shown his yellow card eight minutes after coming on.