George Kittle is hard to stop.

Even when the 49ers tight end wasn’t playing during San Francisco’s first-round bye last week, he was texting Vikings defensive tackle Jaleel Johnson, his former Iowa teammate, about the possibility of Saturday’s NFC divisional playoff game at Levi’s Stadium.

Once the Vikings upset the Saints 26-20 in overtime, the good-natured banter continued this week ahead of Saturday, when Johnson hopes to land his first tackle on Kittle.

“I’m like, ‘Yeah man, we get this win, we’ll see you guys up there,’ ” Johnson said. “I’m looking forward to going up there and seeing him play in person again.”

Kittle’s romps through NFL secondaries have made him look like the next Rob Gronkowski. His 2,430 receiving yards since the start of the 2018 season trail only Kansas City’s Travis Kelce among tight ends. His 4.52-second speed in the 40-yard dash, at 6-4, has made Kittle the ideal “move” tight end, capable of aligning anywhere, blocking anybody and catching anything.

Johnson saw Kittle’s “freak-of-nature” athleticism during Hawkeyes practices before Kittle became a 2017 fifth-round pick by San Francisco.

“Now I feel like people are starting to see the more athletic version of George Kittle,” Johnson said. “It’s good to see. He definitely puts on a good show every Sunday.”

Even if it wasn’t mentioned in this week’s text exchanges, Kittle is aware Johnson and his Vikings teammates have been particularly stingy against his position this season. The Vikings allowed an NFL-low one touchdown to tight ends — a 3-yard score to Denver’s Troy Fumagalli in Week 11 — and put a cap on Kelce (62 yards), Philadelphia’s Zach Ertz (54 yards) and the Giants’ Evan Engram (42 yards) this season.

Safeties Harrison Smith and Anthony Harris, along with linebackers Eric Kendricks and Anthony Barr, have played key roles in limiting tight ends.

“They have a lot of different coverages,” Kittle said. “They focus on tight ends. Whatever Coach [Kyle] Shanahan has schemed up, I’m just going to do that. It’s been working for me so far this year, so I’ll keep doing that.”

Tackling Kittle might be a problem greater than the 49ers’ play designs that spring him loose against NFL defenses. His 622 yards after the catch lead all tight ends — and receivers. His elusiveness will be tested against a sticky Vikings defense that allowed the third-fewest yards after the catch behind only the Patriots and Steelers.

Harris, whose two missed tackles are the fewest in the Vikings secondary, said the defense takes pride in taking down everybody.

“It’s a physical game with him,” Harris said. “That’s our identity.”

Vikings defenders know they can’t look away for long. The 49ers find creative ways to get the ball to Kittle, whose team-high 107 targets are 26 more than the next teammate, rookie receiver Deebo Samuel. Smith, the Vikings’ All-Pro safety, laughed when reminded of the “dead man” play where Kittle cut blocks and falls to the ground, only to pop up when defenders look away and run a route for a catch.

“They obviously have a great offensive staff and scheme there,” Smith said, “but he’s out there making plays.”

Deploying Kittle, also a bulldozer in the running game, has been an enjoyable part of game planning in Shanahan’s third season as 49ers coach.

“It’s been very fun,” Shanahan said. “It’s always important to have a good tight end and I’ve had a few over my career. George is as good as any of them. What’s crazy with George and the difference that makes him so much fun is you can’t decide where you like him more — the pass game or the run game, because he does both at such a high level.”

A dangerous combination of size and speed at every level, led by Kittle, makes the 49ers legitimate Super Bowl contenders despite questions about their inexperience. Saturday marks Kittle’s first NFL playoff start, along with quarterback Jimmy Garoppolo and many other 49ers.

How the Vikings defend Kittle could help determine whether San Francisco’s potential turns into results.

“It feels like another week, but if you lose, you’re done, which is a weird feeling,” Kittle said this week. “We haven’t had that one yet. I’m going to do what I’ve been doing for the past 14 games. I’m just going to play football, and I’m going to have fun doing it.”