The 37-year-old Bryant missed his first game of what could be his final NBA season Tuesday in Miami, saying afterward that he "had trouble walking."
"Still too tight. Still too tight," Bryant said Wednesday. "Stretching it as much as I can. Icing it down as much as I can. Hopefully by Friday I'll be ready."
The Lakers head to Dallas to face the Mavericks on Friday. In order to play, Bryant said, "It's just got to go away. The back pain has just got to go away."
Bryant, whose past three seasons have all been cut short by injury, has attributed the back soreness to 20 NBA seasons of "wear and tear."
"It comes and goes," Bryant said. "First game against Utah in the preseason, my back was tight. Tried to loosen my back up. Next game, it was fine. Then [I] have a couple practices, get in and start playing a little bit, scrimmaging and stuff like that [and] it tightens up. Then it goes away. It kind of comes and goes."
Bryant said his back has never bothered him before.
"This is new," he said. "I've been through worse."
Bryant previously said, though, that he's not concerned.
"It's soreness and something that I can knock out with a little rest, a little treatment," Bryant said Tuesday. "It's not like an injury-injury."
Lakers coach Byron Scott said he wasn't sure how long this issue would linger with Bryant but that he was optimistic Bryant would play against the Mavericks.
"I don't know how this is going to kind of play out. Only Kobe knows that, because he knows his body better than we do," Scott said. "We're just going to play it by ear and the games that he's ready to play, he's going to play. And when he's not [ready] and he needs some rest or he has some ailment that's bothering him, then we'll give him the day off."
Scott also said he wasn't aware of any back issues with Bryant until last week following a practice in New York. Bryant said Tuesday that his back had been bothering him since training camp.
"I don't remember ever talking about it in training camp," Scott said. "He knows his body, so it might have happened in training camp and he just didn't tell us about it because it was very minor."
Scott said he still trusts Bryant to be honest about his body.
"I'm going back to my playing days -- if I had a little bit of a back that was a little sore, if I knew I could play, I didn't tell anybody," said Scott, who won three championships with the Lakers in the 1980s. "You just play. When it got to the point where you can't play is when you have to tell people, 'Hey, this is what's going on.' That hasn't changed."
Bryant is in his final season of his contract with the Lakers and hasn't said whether he'll retire next summer, instead saying that he'll make that decision at the end of this season.
Bryant is averaging 16.5 points on 32 percent shooting this season, which is on pace for his worst shooting percentage since he entered the league.
For the second straight game, Metta World Peace started in place of Bryant.