The Gunners were branded a bunch of babies last season after losing 1-0 in the Premier League at Sheffield United.
Former Blade Phil Jagielka gave them the label after being snubbed at the end.
And Morgan was reported for punching Robin van Persie in the stomach.
Arsenal return to Bramall Lane for tonight's Carling Cup fourth round.
Morgan, 29, said: "It's upsetting when opponents refuse to shake hands. They may not have been happy on the night."