Howard has missed the past three games because of a torn labrum in his shoulder, aggravating an injury he initially suffered earlier this season.
Despite winning the three games Howard has missed, the Lakers (23-26) are 10th in the Western Conference playoff race. They also will be without star forward Pau Gasol, who has a tear in the plantar fascia of his right foot, an MRI revealed Wednesday. The Lakers fear Gasol could be sidelined four to six weeks, a source told ESPNLosAngeles.com.
"We don't have time for (Howard's shoulder) to heal," Bryant said Wednesday in an exclusive interview with ESPNBoston.com's Jackie MacMullan. "We need some urgency."
The interview with MacMullan came one day after Bryant publicly challenged Howard, stating that playing through an injury is "something that you have to balance out and manage."
Bryant also asserted that Howard is preoccupied with how he is perceived by fans and media.
"Dwight worries too much about what people think," Bryant told MacMullan. "I told him, 'You can't worry about that. It's holding you back.' He says, 'OK, OK, OK,' but it's always hovering around him.
"He just wants people to like him. He doesn't want to let anyone down, and that gets him away from what he should be doing."
Bryant also speculated that Howard, in his first season with Los Angeles, may not be accustomed to the Lakers' standards.
"(Howard) has never been in a position where someone is driving him as hard as I am, as hard as this organization is," Bryant told MacMullan. "It's win a championship or everything is a complete failure. That's just how (the Lakers) do it. And that's foreign to him.
"When you think about it, there aren't many organizations that look at it that way. There are only two that can really honestly say that's what they live by -- Los Angeles and Boston."
Howard preached patience in a recent interview with ESPN's Stephen A. Smith, pointing to the fact that Bryant and Shaquille O'Neal needed three years before winning a championship with the Lakers.
But the 34-year-old Bryant, who is averaging 27.6 points per game in his 17th NBA season, is approaching this season with more desperation.
"We don't have three years," Kobe said. "We've got this year."
Howard is listed as day to day, and his status is uncertain for Thursday's game against the Boston Celtics.
The Lakers are hopeful Gasol's injury will prompt Howard to return "sooner than later," a team source told ESPNLosAngeles.com.
ESPNBoston's Jackie MacMullan, ESPNLosAngeles.com's Dave McMenamin and ESPNLosAngeles.com's Ramona Shelburne contributed to this report.