The Arizona Cardinals have two pretty good running quarterbacks on a roster that's surprising the football world as the NFL's last undefeated team.

Everyone knows about the first one. MVP front-runner Kyler Murray's speed and pitter-patter feet are, as Vikings co-defensive coordinator Andre Patterson put it, "like a video game."

No one outside of Waconia, Minn., knows about the second. Probably because he's morphed into one of Pro Football Focus' most beloved NFL tight ends. His name is Maxx Williams, a seventh-year player, ex-Gopher and former 1,500-yards-a-season rusher as Waconia High's signal-caller back in the day.

"I'd have to give that running advantage to Kyler," Williams joked.

And Murray can pass the ball, too. He's completing a league-high 76.1% of his passes while ranking second in yards per attempt (9.5) and fifth in passer rating (115.1).

As for Maxx, well …

"Maxx had probably the strongest arm I've ever seen," said Brian Williams, Maxx's dad, a former coach and New York Giants center from 1989 to '99. "But he absolutely could not throw a football. We used to laugh about it. It was, 'Ready, set, hut,' and he'd drop back and run around the ends."

And then run over defenders at 6-3, 185 pounds.

NFL defenders can only wish Maxx still weighed 185. Just ask the Vikings, who were on the black-and-blue end of the 6-4, 252-pound Williams' career highs for catches (seven) and yards receiving (94) in Arizona's 34-33 victory in Week 2.

"My role? I'm a tight end. We're problem solvers," Williams said. "Need us to block one week, we block. Need us to help in the passing game, we can do that, too."

Pro Football Focus is loving this guy more each week as Arizona has built a 4-0 record heading into Sunday's home game against NFC West foe San Francisco (2-2). According to the league's analytics bible, Williams ranks fourth overall among all tight ends.

Williams has caught 15 of 16 balls thrown his way, including a season-long 34-yarder that was tipped by three Vikings before it found his opportunistic mitts.

"I'm from Pittsburgh," Brian Williams said. "That play reminded me of Franco Harris' Immaculate Reception."

Maxx Williams also has 179 yards receiving — 113 after the catch — and a touchdown, putting him on a pace for 64 catches for 761 yards and four touchdowns. That would shatter his career highs of 32 catches for 248 yards as a rookie second-round draft pick of the Ravens in 2015.

Meanwhile, the Cardinals lead the league in scoring (35.0) and have scored 31 or more points every week.

"I think it starts with K1," Williams said of Murray, a 24-year-old in his third NFL season. "Kyler has really stepped up his game this year to being the leader of our offense, our team. The more confidence he gets, the more our playmakers elevate their games and want to match that juice."

Brian Williams looks at the past two quarterbacks for which his son has played. He sees Lamar Jackson in Baltimore and Murray in Arizona. His conclusion?

"The NFL is a different game than when I played," he said.

Yes, it is.

"Two totally different offenses, but the one thing I would say about both Lamar and Kyler is they really are like watching a video game," Maxx Williams said. "We stress as an offense the scramble drill. Since Kyler's gotten here, we've practiced it all the time.

"If you look across the NFL, the teams that are winning games, they make plays when plays break down. It's almost like the play has two parts: the initial part of the play and then when things break down and all things go crazy, how can you get open and extend the play? Playing with Lamar and Kyler, it's exciting knowing you can make plays even when everything breaks down."

Maxx is a third-generation NFL draftee. Brian was a first-round pick of the Giants in 1989. Robert, Brian's father, was a 28th-round pick of the Bears in 1959.

Robert played quarterback at Notre Dame. He threw the touchdown pass that beat Oklahoma 7-0 and ended the Sooners' famous 47-game win streak.

"Dad decided to go medical school instead of the NFL," Brian said. "When I was younger, I'd say, 'Dad! You played quarterback at Notre Dame. The Bears drafted you. And you didn't play in the NFL!?' As I got older, I realized that was the smartest decision he could have made."

Robert served his country as a flight surgeon in Vietnam. He opened his own practice in Pittsburgh. Unfortunately, he also died before Brian had a son who played quarterback, couldn't throw a lick and still found a way to make a name for himself in the NFL.