The 43-year-old says he is hoping the Blaugrana's prized assets both feature at Camp Nou on Wednesday
The Argentina international has been named in the squad for the visit of los Rojiblancos after shrugging off a thigh injury, but it remains to be seen if the 26-year-old will be handed a starting berth having sat out Sunday's trip to Malaga.
Neymar is yet to start a competitive fixture for the Blaugrana since his €57 million move to Camp Nou but, although such a pairing would make life more difficult for his side, Simeone admits he wants to see them both in tandem for the "spectacle" it would provide.
He told a press conference: "I hope Messi and Neymar both play, for the good of the spectacle, but they have a lot of good players and it's the coach who will decide."
Both teams played out a 1-1 draw in the first game of the two-legged affair last week, but the Argentine coach has revealed he would not be adverse to the proposal of Spain's governing body altering the format to be played over one leg.
He added: "The tie is wide open; but, playing at home and with their characteristics, they’ll take the lead role.
"I would like it if the Supercopa were played over one leg sometime in the future."
Wednesday's match is scheduled to kick off at 22:00 BST.