The 6-foot-9 Jeffries, acquired from New York in the Tracy McGrady deal last February, is in the last year of his contract and will make about $6.9 million this season. He appeared in only 18 games this year -- none after Feb. 2 -- and never found a place in coach Rick Adelman's rotation after joining the Rockets.
A message was left seeking comment from Jeffries' agent, Andy Miller.
Jeffries' release comes the day after Houston acquired center Hasheem Thabeet and point guard Goran Dragic in separate deals that sent Shane Battier to Memphis and Aaron Brooks to Phoenix. Houston also received first-round draft picks in each swap and picked up forward DeMarre Carroll from the Grizzlies.
Thabeet and Dragic did not practice with the Rockets on Friday, because their flights were delayed by bad weather in Memphis and Toronto. Houston has four games in the next five nights, and wasn't sure when either player would see his first action with his new team.
Adelman acknowledged Friday he was "disappointed" to lose Battier and Brooks, two of the team's most popular players with fans and most respected leaders in the locker room.
"We've got 23 games left, and we're all going to have to take up the challenge, try to win games down the stretch here," Adelman said. "Different guys will have an opportunity to step up. Everybody is going to have to do a little bit more, take up the challenge."
Houston was looking to add size inside through a trade after Yao Ming went down early in the season with a stress fracture in his left ankle. Chuck Hayes, at 6-foot-6, is the shortest starting center in the NBA and 7-foot Brad Miller, acquired in the offseason to back up Yao, missed 15 games with a nagging knee injury.
The 7-3 Thabeet has been disappointing since the Grizzlies made him the second overall pick in the 2009 draft. He's averaged only 1.2 points and 1.7 rebounds in 45 games with Memphis this season.
The 6-3 Dragic was averaging 7.4 points and 3.1 assists per game this season with the Suns. He was shooting 42 percent from the field, but only 27.7 percent from 3-point range.
"We're just going to have to see where it all fits when they get here," Adelman said. "Right now, I can't tell you. You never know a player until you see him on the floor with your group. We'll just have to wait and see."
Adelman had 10 players at Friday's abbreviated practice. The remaining Rockets described a somber tone around the team in the aftermath of Thursday's moves.
"Definitely a sad day for our organization," leading scorer Kevin Martin said. "It was tough for us, but I think a lot of us were expecting something to go down. There has been talk since the summertime."
Hayes, in his sixth season in Houston, will try to step into the leadership void left by Battier, a respected 10-year NBA veteran. Hayes talked to Battier for about 15 minutes after the trade was announced.
"As much as we learned from Shane, he learned from us," Hayes said. "Now we've got to take the message that he always kept getting across to us, apply it to these last few games and try and win some."