Mavs needs to push and win the game at home, they need to take the advantage of playing in front of their home crow if they win the game they will have that early rest advantage againts the winner between the Wolves and Nuggets, though OKC also bringing the tough fight and not giving them the luxury of dominating the series.
Honestly speaking, they can't afford to lose the next game because going on game 7 with this strong team, will not be a good idea for them since that's when most teams have choked and lose their opportunity to advance to the next series. If they manage to beat the OKC, I'm pretty sure that they will get a chance to make it to the Finals since they got so far until now but first thing first, they need to knock out the OKC in their next game to secure their spot at the Western Conference Finals, they're all good and playing well hope they really win it this time since they have been in this scenario for too long against the Phoenix Suns.