Using ESPN's BPI power rankings and simulations for the remaining regular season schedule, Tom Haberstroh tweeted Monday morning that the Bucks are 61% likely to face the Bulls in the first round of the Eastern Conference playoffs, with a 34% chance that Milwaukee could instead face the Toronto Raptors.
Chicago currently sits one game ahead of Toronto in the race for the #3 spot, though Toronto does own the tiebreaker between the teams by virtue of being one of the East's three division winners. Note that division champs are only guaranteed a top-four spot, not the top three spots.
As for the Bucks, they remain 2.5 games up on the seventh seeded Nets (who have a game in hand), three games up on the eight seeded Boston Celtics, and four games up on the ninth seeded Indiana Pacers. Considering their relatively weak remaining schedule and the ongoing struggles of teams below them, the Bucks appear a virtual lock to make the playoffs, with most scenarios seeing them retain the 6th spot over the season's final two weeks (insert disclaimer about stranger things happening here). However, losing to the Nets in Milwaukee on April 12 would dramatically increase the likelihood of a slip to the seven spot (and a first round date with the Cavaliers), though it's worth noting that the Bucks all but assured to own the tiebreaker between the teams due to Milwaukee owning a five-game advantage in the conference record tiebreaker. Milwaukee is up 2-1 in the head-to-head with Brooklyn, so they can't lose that tiebreaker even if they lose to the Nets on the 12th.
For more, check out SB Nation's complete summary of Eastern playoff scenarios.