The Australian was booked by referee Nick Walsh after 84 minutes of the match at Tynecastle Park, which Rangers won 2-0 with first-half goals from Alfredo Morelos and Joe Aribo.
The caution was Devlin’s sixth of the campaign so far and, as a result, he is now banned for Hearts’ home match against Ross County on Boxing Day.
The Edinburgh club then host St Johnstone on December 29 and travel to Hibs on January 3 before the Premiership’s winter break.
Scottish FA disciplnary rules state that suspensions for accumulative cautions take effect 14 days after the triggering yellow card is received. Devlin’s was one of 11 bookings during Sunday’s fixture.
“Cammy will miss the Ross County game. You don’t want any of your players to get booked but it’s part and parcel of the game. The wee man has been brilliant for us this season,” said Robbie Neilson, the Hearts manager.
“I thought he was bustling about and being aggressive against Rangers and then he did well in possession as well. I think there is more to come from him because I feel he can be more of a threat offensively. I’m sure that will come.”
Hearts must do without winger Josh Ginnelly this weekend when they travel to Dens Park to face Dundee. The Englishman was sent off for two bookings against Rangers and now serves an automatic ban when his club visit Tayside on Saturday.