Speights, who played for the Sixers from 2008-11, also will help replace center Anderson Varejao, who will miss the remainder of the season after developing a blood clot in his right lung.
The ownership group led by Robert Pera took over the Grizzlies on Nov. 5, and they had been scheduled to pay about $4 million in luxury tax this season with a payroll more than $74 million.
Speights is earning $4.2 million this season, while Ellington's salary is $2 million. So the trade helps Memphis keep its starters, including Rudy Gay and Zach Randolph, together the rest of this season hoping to make another postseason run by trading away reserves.
Ellington, who played at Episcopal Academy, helped Memphis beat Miami on Nov. 11 with a career-high seven three-pointers and 25 points. Selby has played in only 10 games this season.
Memphis gets the 6-10 Leuer, who is averaging 2.4 points in nine games. He was the 40th draft selection overall in 2011 by Milwaukee and was claimed off waivers by Cleveland in July.
Sacramento mayor Kevin Johnson had a stern warning for Seattle SuperSonics fans who are excited about the prospect of the NBA returning to the Puget Sound next season.
"Don't celebrate too early," he said.
The three-time NBA All-Star turned mayor unveiled 19 local investors who have pledged at least $1 million each to be part of a group that would buy the franchise.
Sacramento is up against a group that already has signed agreements with the Maloof family to acquire the Kings and build a new arena for the franchise.
* Chicago coach Tom Thibodeau said Derrick Rose took "the next step" in his return from knee surgery by taking more contact in practice. Rose injured his knee on April 28 in the first game of the Eastern Conference playoffs against the Sixers and had surgery on May 12. He was expected to be out 8 to 12 months.
* The Los Angeles Clippers have agreed to a 10-year extension of their lease at Staples Center. Terms were not disclosed.
The Lakers and Kings are the other tenants at Staples Center.
In Tuesday's games *
At Cleveland, Kyrie Irving scored 15 of his 40 points in the fourth quarter, including several key late baskets, to lead the Cavaliers in a 95-90 victory over the Boston Celtics.
Rajon Rondo led Boston with 17 points.
* At Auburn Hills, Mich., Brandon Knight scored 18 points and Jason Maxiell and Andre Drummond had 11 rebounds each to lead the Detroit Pistons to a 105-90 win over the Orlando Magic, who got 26 points from J.J. Redick.