
The injury occurred midway through the concert -- but we're told Bieber soldiered through the pain and finished the show.
Sources close to Biebs tell us they will know more about the injury today.
Story developing ...

He fell trying to crawl out of his crib. Take the baby back to Canada! No one is impressed.
i love you justin bieber!!! you are sooo cute!
hope your knee is ok!!! love you!!!
get well soon :) XXX
See what happens when "boys" (term to be used loosely) try to dance in high heels?
This kid is SUCH A SISSY
He "soldiered" thru....HAHA! He probably cried like a baby and wanted his mommy and his dolly or blankie to hold.
G-Y BOY
Don't be hate the kid, cause he is successfull and rich at such a young age. If your jelous, you should be ...hes a kid but hes a rich millionaire kid and remember that.
Britney Spears might miss a lot more 'X Factor' auditions ... because she can! Simon Cowell gave Brit damn near free reign in order to sign the pop star to that $15 million deal -- but is it backfiring? We'll tell you what peeps on the set are saying.Plus, Chris Jericho's…