Here are the most significant NFL players who were injured in Week 4:
Josh Norman, CB, Washington Redskins: Norman left the game late in the second quarter with an upper-body injury, and the team announced he was questionable to return on account of a rib injury. Norman was subsequently downgraded to out, and Redskins coach Jay Gruden indicated that the CB would "be out a couple weeks," per ESPN's Lisa Salters.
Trent Williams, OT, Washington Redskins: Williams had to be helped off the field during the first half, and his return was deemed to be questionable, with a knee injury cited as the culprit. He returned in the second quarter.
Rob Kelley, RB, Washington Redskins: Kelley was knocked out of action during the first half, and was first declared questionable to return due to an ankle injury, before subsequently being designated as doubtful to return.
Laurent Duvernay-Tardif, OG, Kansas City Chiefs: Duvernay-Tardif was injured in the first quarter of Monday's game against Washington, and was declared out by the Chiefs due to a knee injury. He was replaced by veteran Jordan Devey.
Dalvin Cook, RB, Minnesota Vikings: Cook went down with a knee injury and was declared out for the remainder of the game. The rookie took a handoff from Case Keenum up the middle of the field for a 10-yard gain before he reached and grabbed for his left knee, thus fumbling the ball. He left the field under his own power, then walked to the locker room with Vikings medical staff for further evaluation. "We're concerned about his ACL, but he's going to get a MRI in the morning," Vikings head coach Mike Zimmer said after the game.
On Monday, Zimmer confirmed what many had suspected: Cook has a torn ACL, and is done for the season. Latavius Murray has indicated he is ready to take on a larger role in the offense with Cook out, despite being less than 100 percent himself.
Chris Carson, RB, Seattle Seahawks: During a run in the fourth quarter, Carson injured his left leg as his lower leg was pinned under a defender as multiple players piled on. Players from both teams gathered around Carson as an air cast was brought out and administered to the rookie before he was carted off to the locker room. Following the game, Seahawks coach Pete Carroll referred to it as a "significant" ankle injury. On Monday, Carroll clarified that it's a fracture in Carson's lower leg. "Unfortunately, he's going to be out," Carroll said.
Marcus Mariota, QB, Tennessee Titans: Mariota was pulled from the game against the Texans during the third quarter, and the team deemed him questionable to return with a hamstring injury. Matt Cassel took over behind center for Tennessee, and with the Texans winning by a large margin, Mariota did not return. After the game, it was revealed that Mariota will undergo an MRI on Monday.
On Monday, Titans coach Mike Mularkey indicated that Mariota's injury is of the day-to-day variety, and he has a chance to play on Sunday against Miami.
Derek Carr, QB, Oakland Raiders: Carr twisted awkwardly as he was being sacked in the third quarter and immediately grabbed for his back. After receiving medical attention on the field, he was able to walk off under his own power. EJ Manuel came into the game as Carr's replacement. After being evaluated in the blue medical tent on the sideline, Carr departed for the locker room for further evaluation. The Raiders subsequently announced that Carr was questionable to return because of a back injury, but he did not. Following the game, Raiders coach Jack Del Rio said Carr had back spasms, and will undergo an MRI to rule out anything more serious.
Monday, Del Rio updated the situation, indicating that Carr had a transverse process fracture in his back, and could be out two weeks or more.
Odell Beckham Jr., WR, New York Giants: After making a reception in the fourth quarter, Beckham appeared to injure his ankle, and was examined on the field. He was helped off the field but returned shortly thereafter. Beckham also suffered a dislocated finger during the game, as he attempted to catch a high pass from Eli Manning. "Yeah. Just popped out. It's not the first time," said Beckham, who had a similar problem to a different finger late last year. "It's not a comfortable feeling. You run off and your finger is out of place." Neither injury is expected to sideline Beckham moving forward.
Julio Jones, WR, Atlanta Falcons: Jones left the game in the second quarter. Despite his wishes to return, he was held out for an offensive series by members of the coaching staff. He later headed to the locker room for further evaluation, and the Falcons originally deemed him questionable to return with a hip injury before later downgrading him to out for the duration of the game.
Monday, Falcons coach Dan Quinn said that Jones' injury was not severe, and given the Falcons' bye week upcoming, he's not expected to miss any games.
Mohamed Sanu, WR, Atlanta Falcons: Sanu was declared out at the start of the second half with a hamstring injury. With both Sanu and Julio Jones out, Taylor Gabriel, Justin Hardy and Austin Hooper became the primary receivers for Matt Ryan.
Sanu's injury will keep him out 2-3 weeks, according to what Falcons coach Dan Quinn told reporters on Monday. However, the Falcons do have their bye in Week 5, which lessens the blow.
Olivier Vernon, DE, New York Giants: Vernon left Sunday's game against the Tampa Bay Buccaneers with an ankle injury after coming into the game questionable with the injury. He tried to play through it before coming up hobbling late in the first half while attempting to rush the passer.
Paul Perkins, RB, New York Giants: Perkins left the game against Tampa Bay in the third quarter with a rib injury, and the team announced he was questionable to return. Later, he was downgraded to out.
Weston Richburg, C, New York Giants: A possible concussion sidelined Richburg in the second half against Tampa Bay, and his return is pending his clearance of the concussion protocol. He was later downgraded to out.
Jeremy Lane, CB, Seattle Seahawks: Lane, who left the field during the Seahawks' first defensive series, was downgraded to out due to a hip injury. He was replaced by Shaquill Griffin, with Justin Coleman playing in the slot. On Monday, the team revealed that it's a groin strain.
Cliff Avril, DE, Seattle Seahawks: Avril was shaken up after attempting to tackle a scrambling Jacoby Brissett in the first quarter of the game. He was attended to on the field before walking off under his own power. The team originally announced that Avril was questionable to return due to a neck injury, before downgrading him to out.
Deyshawn Bond, C, Indianapolis Colts: Bond was carted off with a left knee injury on the second snap of the game, after he stepped on a teammates' foot while being pushed backward. The team has indicated that Bond is out for the remainder of the game. Sunday night, a source told ESPN's Mike Wells that Bond has a torn quad. Adam Redmond replaced him.
Marquise Goodwin, WR, San Francisco 49ers: Goodwin left in the first half to be evaluated for a head/eye injury. The team said that he was questionable to return before downgrading him to out with a concussion.
Chris McCain, DE, Los Angeles Chargers: After being in on a sack of Carson Wentz in the first half, McCain left the field with an injury. The team subsequently announced that he was questionable to return with an elbow injury, but he returned in the second half.
Benjamin Watson, TE, Baltimore Ravens: Watson was knocked out of the game against Pittsburgh, and the club announced that he was in the concussion protocol. However, the Ravens announced that Watson has cleared the concussion protocol and returned in the second half.
Jordan Matthews, WR, Buffalo Bills: Matthews left the game in the fourth quarter of Sunday's game with a thumb injury and did not return. On Monday, the team revealed that Matthews will require surgery, and is out indefinitely.
Kurt Coleman, S, Carolina Panthers: Coleman sustained a knee injury, and the team declared that he was out. On Monday, the team indicated that Coleman has a sprained MCL, and will be out around a month.
Tyler Ervin, RB, Houston Texans: Ervin got shaken up during a punt return in the first quarter. As he headed toward the sideline, he was limping and in obvious discomfort. After being examined by the Texans' medical staff, it was determined that Ervin shouldn't go back into the game, and he was declared out. The severity and nature of the injury remains undetermined.
Julius Peppers, DE, Carolina Panthers: Peppers sustained an undisclosed knee injury during the first quarter and remained on the ground as trainers checked for damage in his right knee. He walked off under his own power and returned to the game midway through the second quarter.
Ramon Humber, LB, Buffalo Bills: At the end of the first quarter, Humber went back to the locker room for further evaluation on a thumb injury and was deemed questionable to return. He had a large wrap on his hand after the game. On Monday, the team revealed that Humber will need surgery, and is out indefinitely.
Colt Anderson, S, Buffalo Bills: An arm injury befell Anderson during the first quarter, and he was taken to the locker room for further evaluation. On Monday, Bills coach Sean McDermott revealed that Anderson will have surgery on his forearm, and is out indefinitely.
Paul Worrilow, LB, Detroit Lions: Worrilow was shaken up on the first defensive play from scrimmage for the Lions' D and was deemed questionable to return. The club is already without Jarrad Davis, who was declared inactive for the game. During the third quarter, the Lions announced that Worrilow was officially out for the remainder of the contest.
Zach Strief, OT, New Orleans Saints: Strief rode a cart back to the locker room after being evaluated for an unspecified injury sustained in the fourth quarter. Strief, who just returned this week from a sprained MCL, appeared to be in pain on the field, but he walked off under his own power before being evaluated in the pop-up medical tent on the sideline. He did not return to the game.
Mike Hull, LB, Miami Dolphins: Hull left the field after being shaken up on a third quarter tackle when a pile of players landed on him. He walked off under his own power. The team subsequently announced that Hull has a shoulder injury and was questionable to return, but he did return in the fourth quarter.
Ty Montgomery, RB, Green Bay Packers: Montgomery left Thursday night's win over the Chicago Bears in the first quarter with a rib injury. Montgomery was off to a strong start with 28 yards on five carries in the first six plays from scrimmage. Initially it was reported that Montgomery had broken his ribs, but it is now believed the injury is not as serious, and Montgomery could play in Week 5, a source told ESPN's Adam Schefter.
Davante Adams, WR, Green Bay Packers: A helmet-to-helmet hit knocked Adams out of Thursday's win over the Bears, and Adams was later taken to the hospital for monitoring. Adams was released from the hospital on Friday, and is now in the concussion protocol. Bears LB Danny Trevathan was suspended two games for the hit.