Plumlee, 28, signed a four-year, $52 million contract last summer but has failed to live up to expectations. He is averaging 2.6 points and 1.7 rebounds while playing just 9.7 minutes per game. Bucks coach Jason Kidd has made him a healthy scratch 16 times since the beginning of December.
Greg Monroe and John Henson have seen a majority of the minutes at center, though the latter has not played in four of the last five games. Rookie Thon Maker has seen an increase in playing time of late, including 24 minutes in Wednesday's loss to the Utah Jazz.
"Any player wants more minutes to get a rhythm. And it's hard being the third center because John and Moose are playing extremely well. It's just patience. Also, he's working hard and he just has to be ready," coach Jason Kidd said last month, per Charles F. Gardner of the Milwaukee Journal Sentinel.
From a functional perspective, this is little more than a salary dump for Milwaukee. Hibbert is playing under a one-year, $5 million contract he signed last summer, and Hawes has a 2017-18 player option for $6.02 million that he is likely to pick up.
Neither Hibbert nor Hawes has had much success in Charlotte this season, and they are not especially good fits for Kidd's aggressive defensive scheme. Hibbert averaged 5.2 rebounds and 3.6 rebounds in 16.0 minutes per game; his production has taken a stark nosedive since being traded from the Indiana Pacers in 2015.
Hawes is averaging 7.3 points and 4.2 rebounds this season, shooting 47.7 percent—his best mark in a half-decade. He may be able to add a little help from a floor-spacing perspective with Maker still developing and Mirza Teletovic struggling from the field.
It's hard to see what the thought process here was for Charlotte. Plumlee is not especially young, nor has he ever been effective in a high-minutes role at the NBA level. His best season came in 2013-14 with the Phoenix Suns, when he averaged 8.1 points and 7.8 rebounds.
While his high-energy nature can be infectious, Plumlee has seen his minutes decrease each of the last three seasons, and he can be a two-way liability at times. In the best-case scenario, the Hornets are acquiring an average backup center who makes $13 million per season—not exactly the best allocation of resources.