NBA insider Marc Stein reports that the Dallas Mavericks and Milwaukee Bucks have had “exploratory discussions” about trading Bobby Portis and Grant Williams.

Stein did point out that the Bucks haven’t been open to trading Portis for Williams in the absence of other players or draft picks.
Both clubs have been having trouble lately; Milwaukee has dropped its last four games. The Mavericks, however, have lost seven of their last ten games.
In July 2023, Dallas acquired Williams as part of a three-team deal with the Boston Celtics and San Antonio Spurs, expecting that his versatility on defense and low usage as a floor-spacing offensive option would allow him to work well with Kyrie Irving and Luka Dončić.
But that hasn’t really been the case.

Williams is playing a career-high 26.5 minutes per game, but even with that, he is only scoring 8.1 points on 41.0 percent of his field goals and 37.3 percent of his three-pointers. His minus-5.1 net rating, according to NBA.com, is the lowest of any Mavericks player who has played at least 20 minutes a game this season. He has struggled on both sides of the court.
The Bucks have had difficulty guarding opponents all season, so Milwaukee is probably hoping that a change of scenery will allow him to regain his defensive prowess. Despite having the sixth-best record in the Association (33–17), their defense has suffered in part from the departure of Jrue Holiday and the addition of Damian Lillard in the offseason.
According to NBA.com, the Bucks’ 116.4 defensive rating is good for 19th place among NBA teams, and head coach Adrian Griffin’s midseason departure hasn’t affected anything. Under Doc Rivers, Milwaukee’s defensive rating is still a pitiful 116.8 after four games.
Even though Portis has continued to be productive off the bench, averaging 12.6 points on 50.0 percent shooting, the Bucks’ front staff may decide to put defense first in order to win another title before the deadline.