Week 1 is, of course, just 1/16 of the season. But for guys on new teams, from rookies to veteran free agents, it's the first chance to show what you've got -- to make a good first impression. Below, you'll find five people who made strong first impressions in Week 1, along with five newcomers who have some work to do after scuffling in the opener.
STRONG FIRST IMPRESSIONS
Kareem Hunt, RB, Kansas City Chiefs
Week 1 numbers: 17 carries, 148 rushing yards, one rushing TD; five catches, 98 yards, two receiving TDs.
Hunt turned what could have been a disastrous first impression into the exact opposite, recovering from a fumble in his first career carry to rack up the most scrimmage yards ever (246) for a player in his NFL debut. The rookie's effort spearheaded Kansas City's upset of the defending Super Bowl champion Patriots. Hunt played well in the preseason and looked great in camp as Spencer Ware's backup. Pressed into the starting role after Ware suffered a torn PCL in late August, the third-round pick looks like a real draft steal for a team that likes to run.
Dalvin Cook, RB, Minnesota Vikings
Week 1 numbers: 22 carries, 127 rushing yards.
I've come to know Cook well -- we were first introduced when he was a senior at Miami Central High School, and I spent a day being around him while he was at the University of Texas on a recruiting visit. Based on my dealings with him, I do not have any concerns about him personally, despite whatever off-field issues might have contributed to his fall to the second round of the draft. He's a very strong and explosive runner. On Monday night, Cook set a franchise record, putting up the most rushing yards by a rookie in a Vikings season opener -- a record that was previously held by Adrian Peterson.
Kenny Golladay, WR, Detroit Lions
Week 1 numbers: seven targets, four catches, 69 receiving yards, two TDs.
His numbers in the three-cone drill (7 seconds) and short shuttle (4.15 seconds) at the NFL Scouting Combine indicated explosiveness, quickness and the ability to change direction -- and that was on full display in Sunday's win over the Cardinals. It's worth noting that Golladay transferred from North Dakota to Northern Illinois, as there's a history of guys who transfer up from smaller to bigger schools going on to have success. I fell in love with this player during our camp tour. The rookie receiver can get separation, will block, has very good hands and excels at adjusting to the ball. I think he'll be a very good red-zone target.
T.J. Watt, OLB, Pittsburgh Steelers
Week 1 numbers: seven tackles, two sacks, one interception.
Watt's three-cone time (6.79 seconds) showed an unbelievable ability to change direction, while his 10-foot-8 broad jump -- the best of any linebacker at the combine -- and 37-inch vertical jump indicated great explosiveness. Watt is also an outstanding competitor who plays hard on every play. In Sunday's win over the Browns, Watt became the third player since 1982 (when sacks became an official stat) to have two sacks and one interception in his first NFL game. He compares favorably to Clay Matthews early in his career, and has a chance to be the Defensive Rookie of the Year.
Marshawn Lynch, RB, Oakland Raiders
Week 1 numbers: 18 carries, 76 rushing yards.
I saw Lynch working very hard at camp, where he also moved well. Unlike fellow veteran back Adrian Peterson, Lynch's quickness hasn't left him. Against the Titans on Sunday, he did not look like someone who'd sat out the 2016 season. In fact, he looked a lot like the Lynch of three years ago. Thanks to him, Oakland had the time of possession advantage in the win over the Titans. This appears to be another strong pickup for a team whose front office does a good job in free agency.
Also considered:Calais Campbell, DT, Jacksonville Jaguars; Tarik Cohen, RB, Chicago Bears; Sean McVay, head coach, Los Angeles Rams; Giorgio Tavecchio, kicker, Oakland Raiders.
WORK TO DO
Adrian Peterson, RB, New Orleans Saints
Week 1 numbers: six carries, 18 rushing yards.
In his Minnesota homecoming, the former Viking did not look like he had the quickness you need to be successful as a running back. One play from Monday night's loss stands out. With 8 minutes left in the game and the Saints facing third-and-goal from the 2-yard line, Peterson came in on a jumbo package. When Drew Brees tried to hit Peterson on the ensuing play-action pass, Peterson was unable to get open, and New Orleans had to settle for a field goal. Consider, also, what happened on the Saints' opening drive: The 32-year-old picked up 9 yards in the Saints' first offensive play. But after he was held to 1 yard on the next play, the rest of the carries in that possession were split between Alvin Kamara and Mark Ingram. The thing is, even if he's not past his prime, Peterson -- who was caught by the camera seemingly expressing unhappiness in an exchange with coach Sean Payton -- is the kind of back who needs 20 to 25 carries per game to be successful. I think his performance against New England in Week 2 will tell you a lot about where he stands.
Eddie Lacy, RB, Seattle Seahawks
Week 1 numbers: five carries, 3 rushing yards.
Lacy, who has famously battled weight issues in recent years, still looked too big in his return to Green Bay. Yes, I know about the weight incentives he had to meet. But the last requirement was reportedly that he weigh 250 pounds or less, and in my opinion, that's too high -- he's not, to me, someone who should be playing running back at 250 pounds. Signed to be an all-everything back who could be an asset on play-action passes, Lacy did not seem to possess the quickness he once had. He's still only 27 and was a 1,000-yard back as recently as 2014. The next four games will speak loudly about his future.
Brandon Marshall, WR, New York Giants
Week 1 numbers: four targets, one catch, 10 receiving yards.
Marshall entered his 12th season with 941 catches -- but he only added one on Sunday. Dallas didn't do anything special against him; the 33-year-old just didn't look fast or quick enough to get open. He'll still catch jump balls, but you wonder if he can run by anyone. Don't be surprised if second-year pro Roger Lewis (six targets, four catches, 54 yards) eventually replaces him in the Giants' game plan.
Stephon Gilmore, CB, New England Patriots
Week 1 numbers: four tackles, one pass defensed.
Gilmore -- who is coming off his first Pro Bowl season, in which he notched a career-high five picks with Buffalo -- really played well against the Patriots in September of 2012. That might have contributed to the team's decision to sign him in March. In his New England debut, however, Gilmore was in the spotlight for the wrong reasons, in particular when he was burned on a 75-yard touchdown pass that gave the Chiefs their first lead in K.C.'s win over the Patriots. It looked like what happened was, Tyreek Hill got behind Gilmore, and Gilmore, maybe figuring Kansas City quarterback Alex Smith couldn't throw the ball that far, eased off, thus leading to the monster score by Hill. The game, in which the Pats surrendered 368 passing yards and allowed Smith to complete 80 percent of his throws, was highly unusual for both Gilmore and fellow cornerback Malcolm Butler. It'll be interesting to see if the Saints target Gilmore this week.
Kyle Shanahan, head coach, San Francisco 49ers
In terms of numbers, Shanahan's head-coaching debut with the 49ers was quite the come-down from 2016, when he was coordinator of a high-octane Falcons offense that averaged 415.8 yards and 33.8 points per game. In Sunday's loss to the Panthers, San Francisco managed just 217 yards of total offense, picking up yards at a terrible clip of 4.0 per play, while converting two of 11 third-down attempts. I think this says much more about the talent level on the roster -- and the difference between having Matt Ryan in Atlanta and Brian Hoyer in San Francisco -- than it does about Shanahan's scheme. Still, I was expecting a bit more on Sunday, to the point that I picked San Francisco to notch a possible upset win. Things won't get any easier for Shanahan's crew in Seattle this week.
Also considered:JC Tretter, C, and Kevin Zeitler, G, Cleveland Browns.
Follow Gil Brandt on Twitter @Gil_Brandt.