Webster has been absent for two months due to an ankle injury, while Burn has not featured since being substituted because of a tight hamstring in the win at Southampton on March 14.
Percy Tau is available after missing last weekend's defeat at Manchester United having been forced to quarantine following international duty with South Africa but fellow striker Aaron Connolly (foot) is doubtful, while Tariq Lamptey (hamstring) and Solly March (knee) remain out.
Everton goalkeeper Jordan Pickford, sidelined of late by an abdominal injury, is back in training but Toffees boss Carlo Ancelotti on Friday said he thought the England international was "not 100 per cent" and that "we don't want to take a risk for this game".
Andre Gomes is ruled out because of the hamstring injury he sustained in the 1-1 draw with Crystal Palace.
Allan could return to action after missing that match through injury, and winger Alex Iwobi is definitely available again having also not been fit for the Palace contest, while Abdoulaye Doucoure, Fabian Delph and Bernard continue their recoveries.
Brighton provisional squad: Sanchez, Steele, White Dunk, Veltman, Webster, Burn, Karbownik, Bissouma, Gross, Lallana, Moder, Alzate, Propper, Caicedo, Mac Allister, Jahanbakhsh, Izquierdo, Trossard, Maupay, Welbeck, Zeqiri, Tau, Connolly.
Everton provisional squad: Olsen, Virginia, Tyrer, Holgate, Keane, Digne, Mina, Nkounkou, Godfrey, Coleman, Allan, Sigurdsson, Gbamin, Davies, Broadhead, John, Richarlison, Calvert-Lewin, King, Iwobi, Rodriguez.