PORTLAND, Ore. -- Not again.
Rose injured his right knee in the third quarter and the All-Star guard, who sat out last season following surgery on his other knee, did not return during a 98-95 loss to the streaking Portland Trail Blazers.
Rose will have an MRI in Los Angeles on Saturday.
"He was in pain and felt like he couldn't push off his right knee," Chicago coach Tom Thibodeau said.
Rose was on crutches in the training room but was not made available to the media after the Bulls squandered a 21-point lead in their second consecutive loss.
The 2011 NBA MVP led Chicago with 20 points, five rebounds and three assists, but was assisted off the court with 3:20 remaining in the third quarter.
He lost his footing while trying to change direction to get back on defense when Nicolas Batum stole a pass from Joakim Noah and started the other way. Rose limped across the court and couldn't put any weight on his knee. After the Blazers scored, he came out of the game during a timeout.
It didn't appear there was any contact on the play, but Rose was unable to return.
"I'm concerned," Thibodeau said. "Anytime anyone goes down, you're concerned. But I don't want to speculate until I have more information."
Rose tore the anterior cruciate ligament in his left knee during the 2012 playoffs and missed last season while recovering from surgery. The top pick in the 2008 draft and a three-time All-Star, he was averaging 15.4 points this season.
"Hopefully, it's nothing serious," teammate Taj Gibson said. "He's a strong guy. He worked extremely hard this summer trying to get his body right, working out every day."
The game was tied at 88 before Kirk Hinrich made two baskets to give the Bulls a 95-91 lead with 3 minutes left. But then Batum knocked down a 3-pointer, Matthews hit a jumper and Aldridge made two free throws to pull it out for the Blazers.
The Bulls led by 21 in the second quarter but were outscored 34-9 in the third as Portland stormed back and took the lead.
"We knew if Chicago continued unopposed, it was going to get embarrassing out there," Lopez said.
Portland was coming off a 4-0 road trip that included a 97-87 win over Milwaukee on Wednesday, but the Blazers looked as though they were going to get blown out in the first half. Chicago jumped out to an early lead and was up 48-27 late in the second quarter before taking a 59-44 advantage into the break. Aldridge was barely a factor, missing nine of his 10 field goal attempts in the first half.
Portland came out strong in the third, erasing the deficit and taking the lead when Mo Williams hit a 3-pointer. The Blazers entered the final quarter with a 78-71 advantage. Portland shot 51 percent in the quarter while Chicago was 4 for 12.
"We didn't change any schemes," Portland coach Terry Stotts said. "We just played harder, played better, played with more focus, more intensity, more attitude."
The Bulls had won five straight before losing to Denver 97-87 on Thursday night in the opener of a six-game road trip.
Bulls G-F Jimmy Butler sat out a second game with turf toe and will miss the entire road trip. Butler and Matthews were teammates at Marquette. ... Portland has won 10 of the last 12 matchups with Chicago at home. ... Aldridge was drafted No. 2 overall by the Bulls in 2006 but got traded on draft day to Portland for Victor Khryapa and the draft rights to Tyrus Thomas.