Brighton will be without Solly March for December after he underwent groin surgery.
The winger missed Saturday's clash and had surgery on Monday.
"He has had some surgery at the start of the week," boss Graham Potter said ahead of the game against Arsenal.
"So he will be (out for) three to four weeks. It was in his groin area and we just needed a bit of work there. It is disappointing for him and for us of course.
"He had pain and the way he plays, he is a sprinter. It is better just to get it cleared up, it was the best option for him.
"It has happened over a period of weeks. It came to a head after the Leicester game. He took a free-kick and just aggravated it a bit more."