Shortly afterwards, McGowan was also sent off for his challenge on substitute Henderson in the corner before Virgil Van Dijk made it 4-0 as Deila’s side secured a semi-final meeting with Inverness Caley Thistle at Hampden on April 18 or 19.
Deila said: “It is stupid to tackle like that on the sidelines. We need to get that out of football.
“It is a youngster standing there with a little trick. You can either stay or go in with both feet, as I see it. You can injure him for life.
“But I have to see it one more time. He (McGowan) must be frustrated. That’s why he did it.
“There were some angry and disappointed players. I spoke a bit to Stokesy. He got a knock in his mouth and was bleeding from the challenge with Paton and he reacted.
“I have to see it again to see if it was a red card. But I was delighted with the game.”
The Hoops beat United 2-0 in the Scottish League Cup final at Hampden on Sunday when Tannadice skipper Sean Dillon was dismissed, adding to the three players – two from United – who were ordered off in the first Scottish Cup match which ended 1-1.
The clubs meet again in the Premiership at Celtic Park on Saturday. It will be a miracle if it passes without incident..