Vonleh, the No. 9 overall pick by Charlotte in the 2014 NBA draft, averaged 3.6 points and 5.1 rebounds in 33 games this season, including 12 starts. For his career, Vonleh has averaged 3.9 points and 4.5 rebounds.
Vonleh, 22 will be a restricted free agent this summer. The trade, which also gave the Blazers a $3.5 million traded player exception, helps Portland get under the luxury tax threshold. The team now has two open roster spots.
Rakovic currently plays in the Swiss Basketball League. He was originally drafted by Dallas in 2007, but has never played in the NBA.
Chicago also received the right to swap second-round draft picks with Detroit in 2022.
Reed was acquired by the Pistons last week as part of the deal that sent Blake Griffin to Detroit. Reed was suspended six games Tuesday after the NBA looked into the circumstances surrounding his arrest last August on a domestic violence charge.
Nelson averaged 5.1 points a game with New Orleans this season before being traded to Chicago last week. He hasn't played since.