Joshua has a big decision to make over his next fight in April, with a heavyweight unification bout against Wilder his preferred option.
However, the pair's respective representatives have previously struggled to agree a deal for the duo to meet and an announcement has yet to be made.
That could leave the door open for Miller, with Madison Square Garden touted as a potential venue should Eddie Hearn and Matchroom Boxing come calling.
"Jarrell is the best American heavyweight, and has always expressed his interest to fight Joshua, so the ball is in his court," his promoter Dmitry Salita told Sky Sports.
"This is one of the biggest possible fights in boxing for 2019. If it happens at Madison Square Garden, it would bring back the heavyweight memories of Mike Tyson and Riddick Bowe, the boxing greats from Brooklyn, New York.
"Jarrell grew up in Brooklyn, it would be a huge event in New York. One of the biggest heavyweight fights in Madison Square Garden, literally and figuratively."
Miller is undefeated with 23 wins and one draw from his 24 career fights, having knocked out Bogdan Dinu in November.
Briton Dillian Whyte is also in the mix to face to Joshua.
Photo Getty Images. Caption: American heavyweight Jarrell "Big Baby" Miller