It's perhaps understandable, after Laquon Treadwell's one-catch rookie season and his 200-yard sophomore year, why some would treat the popular training camp narrative about the 2016 first-round pick's rejuvenation with some skepticism. The proof of Treadwell's improvement, in his final year before the Vikings have to make a decision on his fifth-year option, will come during the regular season. Until then, it might be fair to contextualize his success in camp and the preseason. After an offseason where the 23-year-old said he benefitted from having a better team around him, however, Treadwell has started to provide glimpses of his potential impact that were harder to find in Years 1 and 2. He made an impressive red-zone grab in practice on Wednesday, beating his man off the line and leaping for a Kirk Cousins throw to the back of the end zone for a touchdown. And on Friday night against Seattle, as part of a three-catch, 44-yard performance, Treadwell had a 27-yard catch-and-run that ranks as his longest in a Vikings uniform. He beat a jam from cornerback Akeem King off the line, settling down in front of King in coverage to catch a 13-yard Cousins pass, then adding another 14 yards after the catch to give the Vikings a first down at the Seahawks' 28. For the preseason, Treadwell has six catches for 55 yards. It seems as though the 23rd overall pick in 2016 will get plenty of chances to make his mark this season as the Vikings' No. 3 receiver. For Treadwell to stick around beyond his rookie contract, he'll have to produce when the games count — especially with Stefon Diggs signed to a five-year, $72 million deal and Adam Thielen in the second year of a four-year contract that could be reworked after the season. What Treadwell has done heading into the 2018 season, though, at least provides a hint he could be on the verge of a step forward. Here are some other notes and observations from the Vikings' third preseason game: Punt coverage struggles again: The Vikings were able to come back and win in large part because a penalty negated what would have been the second punt return TD they've allowed in the preseason. A holding call wiped out David Moore's 75-yard return up the middle, which would have put Seattle up 27-13 in the fourth quarter. The Vikings allowed a 75-yard return touchdown against Denver, and a 56-yarder that set up a score last week. Coach Mike Zimmer said after the game he was "concerned about the coverage units," and the Vikings will look to shore their punt coverage up, in particular, before the regular season. Eight-man boxes stifle running game: After finding plenty of success on the ground in the first two weeks of the preseason, the Vikings carried 24 times for just 58 yards on Friday night. They found running room harder to come by, Zimmer said, because of the Seahawks' typical defensive scheme, which favors eight-man boxes in front of a Cover-3 shell. "You're going to have to get a hat on a hat and the back is going to have to beat a guy," he said. "Playing those kind of teams when you're running, it's always going to be a hard day of going. I'm not concerned." Seahawks seemed to come with a plan: The Vikings will see the Seahawks again in Seattle on Dec. 10, so they might not have wanted to tip their hand much on Friday night. Zimmer, though, thought the Seahawks had done some game-planning for the Vikings, specifically with the two trap runs they called to attack defensive tackle Sheldon Richardson, who played in Seattle last year. "It's pretty obvious they game planned us because some of the plays that they had in there, which is fine," Zimmer said. "I don't care if they game plan or don't game plan but they were running — they ran three screens, they ran their flash play. The tight end came up inside, you know, and they've never done that. They were doing that to attack and then the two traps to attack Sheldon [Richardson]. I have pretty good confidence in our guys." Barr making progress as pass rusher: The Vikings deployed their new 3-3-5 defensive set on several occasions Friday night, positioning Anthony Barr close to the line of scrimmage as a pass rusher. Zimmer said the linebacker, who has been working with defensive line coach Andre Patterson on his pass rushing skills, has continued to improve. "It's like anything else — you get used to doing it and then you become better at it," Zimmer said. "He's had some really good rushes in practice. He had a good rush tonight too. The ball got out but he had a really good rush."