Per nfl:
“The Emergency Third Quarterback must be on the club's 53-player roster; the player cannot be an elevated Practice Squad player. The club's starting quarterback (QB1) and its backup quarterback (QB2) must also be on the club's 53-player roster.”
They would need to sign Malik to the 53 for Mac to be emergency qb.
In May, NFL clubs approved 2023 Bylaw Proposal 1A that permits each team to dress a 49th player as its Emergency Third Quarterback. The following procedures are in place for use of an Emergency Third Quarterback in a regular or postseason game.
www.nfl.com