The Nets and Mavs were involved in a minor trade yesterday: “The Nets acquired Kris Humphries and Shawne Williams from the Dallas Mavericks in exchange for Eduardo Najera. In a separate move, the Nets waived forward Sean Williams. Humphries should immediately enter the Nets rotation as the first big man off the bench. In six NBA seasons, he has modest numbers but, at 24, is viewed as a young, athletic player who still has room to grow. His minutes (12.6 per game this season) should increase with the Nets. Humphries’ entrance corresponds with the exit of the often-injured Najera, 33, who was signed by the Nets in 2008 to provide a veteran presence but wasn’t on the court nearly enough to make much of an impact. With the Nets devoting minutes to their younger players, Najera became expendable — he appeared in just 13 games this season. Sean Williams, in his third season with the Nets, entered the league as the team’s first-round draft pick in 2007, with loads of potential. But after 2 1/2 unfulfilled years, on and off the court, the athletic big man is headed out of New Jersey with career averages of 4.3 points, 3.5 rebounds and 1.2 blocks per game.”