Maddison was speaking after he netted a brace in Leicester's 4-0 win over Forest on Monday night to take his tally to five goals in seven games.
In his post-match interview, Gary Neville asked Maddison for his reaction to claims he "wouldn't be a good traveller" if he was given a bit-part role for the Three Lions.
Maddison refuted the claims saying: "I've never seen anything like that but that's almost questioning my personality and my professionalism which is obviously quite insulting."
Despite the door remaining shut on a recall before November's kick-off in Doha, Maddison is optimistic he can force his way into Southgate's squad.
"I'm not naive, I know there's top players in those forward areas. But I have a self belief and a confidence that I'm a top player and I can be in that category. I've got to have the mindset of I'll force my way in," Maddison told Sky Sports.
"I think there could be a space for me so I'll just keep working hard, producing performances for Leicester and the gaffer here and see where it leaves me."