The Nets sent the Wizards $3 million to complete the deal, according to league sources.
The move allows the Nets to clear another $3 million in cap space to spend on free agency this summer.
Yi is scheduled to make $4.1 million next season. Ross is set to make $1.1 million. The Nets should now have roughly $30 million in cap space to spend after the move, according to sources.
They will have to clear even more cap space, however, to sign two free agents to league-maximum deals. LeBron James, Dwyane Wade and others are projected to earn $16.6 million in first-year salaries. So a team would need to be $33.14 million under the cap to sign two max-contract free agents. The Nets are close, but they aren't there yet.
The trade is the latest in a series of moves in which the Wizards are using potential salary-cap space to acquire assets instead of free agents. Last week, the Wizards agreed to acquire Kirk Hinrich from the Bulls for the draft rights to Kevin Seraphin.
Yi is expected to compete for a starting position with forward Andray Blatche, who broke his foot this summer and will be out of basketball-related activities for the next three months.
"I think we're concerned about our own situation, and this fits in with our plan of adding young players, players that can be part of a core going forward," Wizards president Ernie Grunfeld said. "We've got a player who's had success in the NBA and at the same time is only 22 years old."
Yi was the No. 6 pick in the 2007 draft by Milwaukee and has now been traded twice. He averaged career highs of 12.0 points and 7.0 rebounds last season, but was limited to 51 games because of injury.
The forward from China has averaged 9.6 points and 5.8 rebounds in his career. The Wizards used a trade exception to complete the deal, again bringing in a player when many teams have preferred financial flexibility ahead of free agency.
"We made a decision that we're going to save some of our powder for the future and try to right now put a core of young players together that can grow and we can build with, and that is the reason that we do have those opportunities right now," Grunfeld said. "Otherwise, they probably wouldn't be there for us."
New Jersey may have found Yi's replacement when it drafted Derrick Favors from Georgia Tech with the No. 3 pick, or could target another power forward in free agency.
Ross spent last season with the Dallas Mavericks and Washington, and also has played for the Clippers and Memphis Grizzlies in his six-year career. He holds career averages of 4.3 points and 2.2 rebounds.
Chad Ford covers the NBA for ESPN Insider. Information from The Associated Press was used in this report.