Chicago Bears MLB Brian Urlacher will continue missing practice time at training camp with one goal in mind.

"September 9 I'll be ready to play," he said Sunday at Bourbonnais, Ill., about the regular-season opener. "I'm pretty sure.

"That's really all that matters to me.  Preseason games and all these practices, I'd love to be out there, but I'm not going to put myself in jeopardy and miss the first game."

Urlacher set no timetable for his return to practice but described the pain in his left knee as somewhat mysterious. He sprained the MCL and partially sprained the posterior cruciate ligament in the Jan. 1 regular-season finale last season at Minnesota but didn't have surgery. The 34-year-old, eight-time Pro Bowler rehabbed the injury in the offseason without a problem, then returned to practice at the start of training camp.

"I practiced the first four or five days and it felt pretty good and it got sore and a little swollen so I'm taking some time off right now," Urlacher said,

Urlacher hasn't sought an outside opinion on the knee, saying "Our doctors are the best. I trust what they say, our trainers. I just do what I'm told to do."

The Bears haven't had Urlacher for a full practice since July 31, although he did go through individual technique sessions of a couple practices in early August before sitting out practices entirely. He also left camp and missed two practices, and also the first preseason game with Denver for what coach Lovie Smith had said were "personal reasons," unrelated to his knee.

Asked about those absences, Urlacher said, "It was a personal reason, just like coach Smith said."

While Urlacher trusts in the Bears doctors and trainers, he seemed uncertain about what exactly causes the pain.

"I have no idea," he said. "It's hard to tell with an injury like I had what causes it and why it's doing this."

There's no telling if the situation is one where he'll have to manage pain throughout the season or it will eventually go away with rest. Also, there's no telling if he can return to play 100 percent healthy.

"I hope it's 100," he said. "I mean, I felt great coming into training camp."

Urlacher wears a 14-ounce brace on the knee in practice.

"The brace doesn't allow me to do a lot of things," he said. "But I still ran pretty fast, and I moved around pretty good."

For now, the Bears continue to use strong-side LB Nick Roach in the middle and Geno Hayes in Roach's spot.

Follow Bears reporter Gene Chamberlain on Twitter @CBSSportsNFLCHI.