Everton went into their Premier League game against Southampton on Sunday top of the table and with the only unbeaten record in England's top tier.
But they were well off the pace as they succumbed to a 2-0 defeat.
James Ward-Prowse opened the scoring after 25 minutes, with Che Adams getting the home side's second 12 minutes later.
He made contact with Kyle Walker-Peters and consequently received his marching orders.
Digne was not happy at all. He protested heavily before reluctantly making his way off the pitch.
Everton's manager, Carlo Ancelotti, also raged about the decision after the game.
During Everton's match against Liverpool last week, Jordan Pickford escaped a red card for a challenge on Virgil van Dijk, while Richarlison was sent off for a tackle on Thiago.
And the Italian boss suggested that the referee's decision to send off Digne against Southampton was influenced by two incidents in the Merseyside derby.
"It was a joke - it was not intentional," he told Sky Sports. "It was not violent conduct so they could've checked better. Maybe all the rumours during the week against [Jordan] Pickford and against Richarlison affected the decision, and if it is like this, it's not right. It's not fair.
"I think we're going to appeal. It could be a yellow card but it wasn't violent conduct and the red card was unfair.
"It was not a bad challenge I saw - it was not intentional as he was running behind and he had a contact with the ankle of the opponent but he didn't have the intention to use violent conduct, so it was not the right decision."
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