Leicester boss Craig Shakespeare said that Gray and Slimani had given him 'food for thought', as both players performed well during the Carabao Cup game at Sheffield United, which they won 4-1.
Gray scored one and Slimani two and they are being considered by Shakespeare to lineup against the Red Devils.
"He's given me food for thought. The idea before the game was to give the squad players the game time they needed and they answered in the right way", Shakespeare said on winger Gray.
"Centre-forwards will be judged on goals and their team ethic - he's done his chances no harm", he said of Slimani.
However, Gray has been linked to Bournemouth, and Slimani has received interest from Sporting Lisbon. "At the moment there is speculation about a lot of players but until we get an offer that's accepted, we carry on as normal", the Shakespeare added.