Martial starts as Lukaku, Young return for Manchester United
Romelu Lukaku and Ashley Young have also been named for their first starts of the new Premier League season at the expense of Marcus Rashford and Matteo Darmian, who drops out of the squad, respectively.
Martial was linked with a move away from Old Trafford in the last transfer window and was an unused substitute in the opening win over Leicester City at Old Trafford.
"We know Anthony well and you can expect always good things from him," Jose Mourinho told the club's official website. "He can find that stability that makes great players, we try to help [him] and he's working well.
"Alexis was going to play but he had a little problem, so we had to decide to give an opportunity to another attacking player."
As for Brighton, who lost away at Watford in the opening round of matches, Chris Hughton has selected former Barcelona full-back Martin Montoya for his debut.
changes from the opening day win over Leicester - what do we think, #MUFC fans? #BHAMUN pic.twitter.com/9JvGhIatg9
— Manchester United (@ManUtd) August 19, 2018