Injuries have arguably been the defining characteristic of the first three weeks of the NFL season, and Week 3 hit particularly hard. David Montgomery exited the Bears-Texans game early with a knee/ankle injury, which might make Khalil Herbert the must-add player on the waiver-wire heading into Week 4. However, that was far from the only injury we saw Sunday that will send Fantasy players to the waiver wire. 

In fact, in 29% of CBS Fantasy leagues, Herbert might not even be the top player to add – because that's how many leagues Alexander Mattison is still out there in. Mattison could be in line for a very valuable role after we saw Dalvin Cook exit Sunday's game against the Lions in the third quarter with a shoulder injury. That's an especially concerning injury for Cook, who has a long history of shoulder issues dating back to college. However, according to NFL Network's Tom Pelissero, Cook suffered a dislocated shoulder and is expected to be fine moving forward. The expectation is that Cook will wear a harness and the Vikings are hopeful he will be able to suit up next week against the Saints.

However, if Cook is forced to miss next week or beyond, we need to be prepared. We've seen what it looks like when Mattison gets a chance to start for the Vikings, though that was in the Mike Zimmer offense, which was more run-heavy than the new-look Vikings. Still, Mattison has done a pretty convincing Cook impersonation in six games Cook has missed over the past four seasons, averaging 20.4 PPR points per game, with 79.5 rushing yards on 20.2 attempt plus 36 receiving yards on 3.8 catches per game – since 2019, Cook is averaging 92 yards on 19.5 attempts with 34.5 receiving yards on 3.2 catches. 

Hopefully, the injury will end up minor for Cook. He had a torn labrum and separated shoulder in Week 12 last season but ended up missing just one game. He's played through these recurring injuries, so it's possible this ends up being just a one-week absence – early indications are this isn't considered a serious issue. 

There is still uncertainty surrounding the injury. What we do know is, if Cook is out, Mattison is going to be a top-12 RB. So, even if Cook's injury ends up being minor, this is just another reminder that Mattison remains very much worth stashing on your bench because he's always one Dalvin Cook injury away from being in your lineup.

There were plenty of other injuries around the NFL in Week 3, because of course there were. Here's what we're following coming out of Sunday's games:

Mac Jones (ankle) 

Jones threw an interception on his last play of the game and came away with a pretty bad limp -- he tried to hop, one-footed to the sidelines. It's not clear what the injury was, but he could not put any weight on his left leg as he was helped to the locker room for evaluation. It looked like one of the Ravens defensive linemen fall on his ankle as he hit him. We'll learn more in the coming days about the injury, however, because it's the Patriots, we probably won't learn that much -- at least, not until they have to tell us something. 36-year-old veteran Brian Hoyer has spent seven years with the Patriots but has started just one game, and he's a pretty uninspiring option, as most career backups are. There isn't much to get excited about with this offense even with Jones healthy, and that won't change if Hoyer has to play. 

David Montgomery (knee/ankle)

I wrote about Montgomery's injury here, and with early indications suggesting Cook's injury isn't considered especially serious, Khalil Herbert will likely end up being the top waiver-wire target heading into Week 4. He's looked good in this offense overall, including in two starts last season when he had 245 yards and a touchdown overall. He'll be a borderline top-12 RB if Montgomery misses time. 

Michael Thomas (foot) 

Thomas left Sunday's game and initially tried to work through it on the sidelines before eventually being sent to the locker room for more treatment. He was downgraded to a doubtful return later on and ultimately did not come back. It's not clear if this injury is related to the ankle injuries that sidelined Thomas for much of the past two seasons, but it's hard not to think that way when you see Thomas dealing with any kind of lower body injury. Chris Olave caught nine passes for 147 yards with both Thomas and Jarvis Landry leaving Sunday's game early. 

Tua Tagovailoa (head) 

Tagovailoa was forced to leave Sunday's game in the second quarter, and it was a pretty scary sight, as he took a hit and then stumbled as he tried to walk to the sidelines. He was taken to the locker room for testing before being cleared to play, and he finished the game without incident. The NFL Players Association has told the NFL it wants a review of the concussion protocols as a result of Tagovailoa's clearance, and we'll keep an eye out over the next few days to see if Tagovailoa has any recurrence of symptoms. He finished the game 13 for 18 for 186 yards and one touchdown through the air. 

Tee Higgins (head)

Higgins was also briefly forced to leave Sunday's game for concussion evaluation, though he was ultimately cleared to return as well. Because Higgins suffered a concussion in Week 1, it'll be worth keeping an eye on this one as well over the next few days. He's been tremendous when healthy, with five catches for 93 yards on seven targets Sunday -- and he could have had a truly massive game if not for an iffy overturned touchdown. 

Jarvis Landry (ankle)

Landry's injury seems less serious than Thomas', if only because he was originally announced as probable to return. That, of course, isn't a science, and we'll need to see how the next few days go. He could be worth using if Thomas has to miss time, or he could push Olave into an even more prominent role in the Saints offense.