Favors, who averages 12.9 points, nine rebounds and anchors Utah's interior defense, has played in parts of six games since being injured in the opening minutes against the Pistons.
Since Feb. 12, Favors has played a total of six minutes all against Philadelphia in the game before the All-Star break.
"It's tough," Jazz coach Tyrone Corbin said. "We need all of our guys on the floor. He came back and tried to go and was feeling OK But ... this is one of those things that hangs around."
The bottom line?
"We'll give him some more time," Corbin said, "and see if we can get it to heal."
Jazz miss their rim protector
Favor's absence was noticeable in Brooklyn's 105-99 victory over the Jazz on Wednesday night.
The Nets shot 50 percent from the field and center Andray Blatche scored a season-high 25 points mostly by going to the rim or popping free on pick-and-rolls.
"I thought defensively we were OK for awhile there," Corbin said. "... They got us out of our offense and defense by getting physical with us and we have to respond better to that."
The Jazz, incidentally, are 0-7 without Favors.
Blazers will be tall order
Portland is 2-0 against the Jazz this season after a pair of easy wins: 130-98 and 105-94.
The Trail Blazers have slipped to fifth in the Western Conference, however, after losing seven of their last 10 games.
Portland comes off a 111-109 loss to San Antonio on Wednesday night, which was its third straight defeat.
"They are still a very good team," Corbin said. "... We have to make sure we understand we can't let them get out in transition and get easy baskets. They are going to push the tempo. They are capable of scoring a lot of points in bunches. So we have to make sure we control the game."
Portland will be without All-Star forward LaMarcus Aldridge, who has been sidelined with a groin strain. He is seventh in the NBA in scoring (23.9) and rebounding (11.4).
Meanwhile, the Jazz hope to improve on their 7-19 road record. No team in the Western Conference is worse away from home.
"We're getting better," Corbin said. "We've made some strides. With young guys in this league, man, you take a couple of steps forward and you may take a step back."