Fooch's Note: Update coming, but Adam Schefter now saying Alex Smith will NOT PLAY.
Although Alex Smith is listed as questionable, it is not particularly shocking to note that the 49ers QB is expecting to play on Monday Night Football. The proverbial "source with knowledge of the situation" told Pro Football Talk that "Smith intends to play on Monday night against the Bears, and that it would be a surprise if he doesn't."
PFT also told us he was getting a second opinion, which may or may not have been accurate depending on the definition of "second opinion" in the context of the NFL's concussion protocol. Nonetheless, this news is not particularly surprising. Smith has been listed as limited all week, but getting cleared to practice in any context is a big deal. Bears QB Jay Cutler was not even cleared to practice, so there's your difference right there.
According to Jay Glazer (via PFT), the final test was a contact test that involved hitting Smith in the helmet with a pad and determining if any concussion symptoms recur. That seems like rather imprecise testing, but I'm not the doctor here, so we'll have to take it for what it is.