Many members of the Vikings offense enjoy knowing Gary Kubiak's playbook, a much-needed element of familiarity in an oddly truncated NFL offseason. One position, however, is largely an exception.

Of the Vikings' 10 receivers, five are newcomers to the team — and only five have ever caught an NFL pass. Behind veteran Adam Thielen, the green targets have started to separate themselves, especially in padded practices that began Monday.

The main addition to the rebuilt receiving corps — first-round draft pick Justin Jefferson — already has turned heads.

"I was telling him [Sunday], his releases were crazy," second-year receiver Olabisi Johnson said. "He was working everybody off the line. We knew coming in this guy was going to be a star, and he's proven just that."

The roster's youth movement mostly reaches quarterback Kirk Cousins at receiver, where he's thrown primarily to a first-team rotation of Thielen, Johnson, Jefferson and Chad Beebe in training camp. Tajae Sharpe, the ex-Titan signed in free agency, has mostly worked with backups, followed by K.J. Osborn, Alexander Hollins, Dillon Mitchell, Quartney Davis and Dan Chisena.

In the shadow of the Stefon Diggs trade, those Vikings receivers combine for the fifth-fewest catches of any NFL receiving corps, ahead of only offenses in Denver, Washington, Baltimore and Pittsburgh.

The collective inexperience means Jefferson, who came out of a record-setting LSU offense, is set up well to win a starting job. But Kubiak is keeping focus on the whole competition.

"We got a month," he said. "So, we're going to find out. We're going to let these guys compete. Obviously, from a receiver standpoint, we're going to probably play four guys throughout the course of the game."

Jefferson has kept up, if not outpaced, teammates so far, despite a nearly two-week delay to his training camp. Jefferson spent 10 days quarantined in a nearby hotel while on the reserve/COVID-19 list; the duration of his absence indicated a positive test, but Jefferson declined to talk specifics.

He said he wasn't allowed to work out in quarantine, confined to virtual meetings and his PlayStation. His Aug. 4 return was "hard," he said, but he's since impressed teammates and coaches alike. He's shown a "knack for knowing where the open areas are," according to coach Mike Zimmer.

LSU's pro-style offense under Joe Brady, now the Carolina Panthers' offensive coordinator, has aided Jefferson's transition.

"We pretty much ran the exact same offense, just different terminology," Jefferson said. "Actually, being in that pro-style offense last year, it kind of helped me with what I'm going through now. It's kind of easier to pick up plays, concepts, so just being here is kind of making my life a little bit easier."

Jefferson is playing every receiver position, but he ran as the Vikings' slot receiver in three-wide formations at times in Monday's practice. He's sharing that spot right now with Beebe, the third-year receiver who was injured in September and is coming off ankle surgery.

But it's been Johnson getting the lion's share of starting reps opposite Thielen in camp. A seventh-round pick out of Colorado State last year, Johnson made the most of his chances, catching 31 passes for 294 yards and three touchdowns while replacing an injured Thielen in six starts.

This offseason, Johnson trained back home in Colorado with Broncos quarterback Drew Lock and receivers Courtland Sutton and Tim Patrick, among others.

While the pandemic ruined many training schedules, Johnson said working with other pros kept him up to speed ahead of his second year.

"You get about three padded practices under your belt, the game slows down, it gets hard," Kubiak said. "Guys get worn out; it gets physical. So, that's when players really start to separate themselves."