James laughed when asked about Bryant's poor performance and harsh self-criticism and told the Akron Beacon Journal, "He knows he don't suck."
"What I see is a challenge to himself," James told the newspaper. "It has zero to do with his age. Zero. I think at one point in my career, in my 20s, I felt like I sucked. It's all a personal challenge."
Bryant, 37, called himself "the 200th-best player in the league right now" on Sunday after struggling in a third straight start to open the regular season, his 20th with the Lakers.
"I freaking suck," Bryant said after the Lakers lost to the Dallas Mavericks.
Through the Lakers' 0-3 start, Bryant averaged 17.3 points per game but shot 31.3 percent from the floor, including 20.7 percent from 3-point range. In Los Angeles' 120-109 loss to the Denver Nuggets on Tuesday, he scored 11 points on 4-for-11 shooting (36.4 percent), including 1-for-5 (20 percent) from 3-point range.
Bryant recorded more fouls (five) than field goals, air-balled two 3-pointers and had another shot that failed to draw iron.
"[Been] sitting for 30 minutes, man," he said when asked about those shots. "Coming into the game a little tight."
Where do the Lakers go from here?
"We just keep working," coach Byron Scott said. "That's all we can do."
Scott added: "He'll figure it out. Kobe is the last person that I worry about."
James isn't worried about Bryant, either.
"I know him. He knows he don't suck," James said. "C'mon, man, it's Kobe Bryant. But it's a personal challenge to him. That's all that is."
ESPN.com's Baxter Holmes contributed to this report.