According to TMZ Sports, J.R. Smith is in talks to join the cast. Per TMZ, Smith's representative Daniel Hazan said that their is 'mutual interest'.
J.R. Smith -- Tapped for 'Space Jam 2' Role ... Let's Get Animated! https://t.co/0mEsUIKDJF— TMZ Sports (@TMZ_Sports) May 8, 2016
Per the report, Smith might voice an animated character, meaning he might voice one of the Monstar' if they again make an appearance in the second movie. It's also possible - and honestly more fun - that Smith could make a cameo as himself as one of the players who has their powers stolen.
I mean, imagine one of the Monstars taking Smith's ability to shoot from anywhere and anywhere on the floor. Smith could then voice the Monstar who takes his abilities too.
Really, the more J.R. the movie has, the better.