Bell: Brady's injury just one of many in Week 1

Tom Brady, QB, Patriots: In case you've been living under a rock, Brady was hurt within the first eight minutes of New England's season opener and will soon undergo season-ending surgery. But that's all we know. Actually, we also know that it was Brady's left knee that was injured because we saw it on television when Kansas City Chiefs safety Bernard Pollard made the hit. It is the Patriots we're talking about here, so information is hard to come by. Brady underwent further diagnostic tests to confirm the nature and severity of the injury, but other than informing the media that he faces surgery, no more details have been made available by the Patriots.

There were several indications that the news was not good. First, Brady, who rarely stays on the ground after a hit, did not bounce back up. Instead he remained on his back, holding his knee close to him, until the medical staff arrived. Even Pollard said that when he heard Brady scream, he knew that he was in a lot of pain.

Second, ESPN's Trent Dilfer reported that a Patriots player indicated Sunday that Matt Cassel would be their quarterback for the rest of the year.

Without knowing the extent of damage Brady will need repaired, it is difficult to project a time frame. At least fantasy owners know that for the 2008 season, it is time to find a replacement.

Vince Young, QB, Titans: Another quarterback was spotted writhing in pain Sunday after taking a hit to his lower extremity. The early word out of Tennessee is that Young has a sprained left knee that could cause him to miss two to four weeks. The Tennessean reports that indications are that the injury is to Young's medial collateral ligament (MCL), but that coach Jeff Fisher does not believe it to be serious.

If indeed Young did suffer an MCL sprain, a relatively common injury for quarterbacks, the reported time frame is certainly feasible, although we might see him sporting a brace on that leg when he returns.

Young has had his share of injuries in his short career, and even entered this contest with a bothersome hamstring. According to the Tennessean, Young told Fisher that the hamstring was feeling tight just minutes before he suffered this latest setback.

Marion Barber, RB, Cowboys: Fantasy owners have to be thrilled with Barber's Week 1 performance. If you weren't sure whether he was a top-five running back prior to the start of the season, his effort had to bolster the argument on his behalf.

Fantasy owners had to be less than thrilled though to hear that Barber sustained a rib injury during the game that forced him out in the third quarter against Cleveland. There is some good news though. Initial x-rays revealed no fracture. Instead, the team is describing it as a rib cartilage injury, according to the Fort Worth Star-Telegram. Make no mistake about it, this is a painful injury. The rib cartilage is affected every time Barber takes a breath, reaches, twists or bends, and the injury will certainly keep him from moving much for the next few days. The Cowboys have expressed that they believe he will be able to play next Monday night, but this will be a day-to-day assessment.

Joseph Addai, RB, Colts: You never like to see a player leave with what is termed a "head injury," but that is exactly what happened to Addai in the fourth quarter against the Bears. It appears that the injury was not severe as he was cleared to return later in the game, according to head coach Tony Dungy as reported in the Indianapolis Star.

Addai finished the night with less than stellar stats, but what jumped out to me was the fact that he did not finish the game in Week 1 of 2007 either. Addai has been forced out of several games early, and does always seem to be on the verge of something big (and I'm not talking about scoring). If your heart rate can stand the strain of worrying about whether his health will hold up, then he should stay on your roster. But don't expect the pattern to change.

Dallas Clark, TE, Colts: Clark left Sunday night's game in the first quarter with a reported right knee injury and did not return in the second half. No more details are known at this time, but we should know more as the week progresses.

Nate Burleson, WR, and Maurice Morris, RB, Seahawks: Burleson was the primary receiver for quarterback Matt Hasselbeck this week with Deion Branch and Bobby Engram out due to injury. Not for long. Burleson left in the third quarter against Buffalo with what the Tacoma News Tribune called a sprained left knee. It turns out it will require season-ending surgery.

Brodie Croyle, QB, Chiefs: Croyle left the game in the third quarter Sunday with what the Kansas City Star reported to be a separated right (throwing) shoulder. Croyle was seen in a sling after the game and will likely miss time, although the team has not issued a time frame.

A shoulder separation results most often from a hard fall on the point of the shoulder. Hmmm. Funny that this is one of the most common quarterback injuries, along with concussions, showing that quarterbacks' heads and shoulders do better when they can avoid being driven into the ground. Most minor separations, which are really sprains of the acromioclavicular (AC) joint where the clavicle (collarbone) meets the point of the shoulder (acromion), can be treated nonsurgically. This appears to be the plan for Croyle. Severe separations that result in chronic pain or inability to throw can require surgical stabilization (which is what 49ers quarterback Alex Smith underwent in 2007), but that is relatively rare.

Stephania Bell is ESPN.com's injury expert. She is a physical therapist who is a board-certified orthopedic clinical specialist and a certified strength and conditioning specialist.