With free-agent acquisition Sammy Watkins and speedy Tyreek Hill catching passes from bazooka-armed, second-year quarterback Patrick Mahomes, the Kansas City Chiefs are poised for a potent vertical offense.

But who is their fastest big-play threat?

Watkins said it's Hill, the first player in NFL history to have a play of 60 or more yards in five straight regular-season games.

"I know for a fact that no one in the league is faster than him," Watkins said.

Hill ran a 4.26 40-yard dash at his college pro day. While at Coffee High in Douglas, Georgia, he ran the 200 meters in 20.14 seconds in 2012 -- the second fastest high school mark at the time and one that would have placed him sixth at that year's Olympics Games.

"My time's not close to that," Watkins said. "If it was a 10-yard, I might beat him."

Watkins ran a 4.43 at the 2014 NFL Combine and won the AA state title in the 200 meters while at South Fort Myers High in Florida. While running sprints during practice, Watkins once surprised Hill by jumping in front of him, but they haven't officially raced.

However, Hill, whose Twitter handle is @cheetah, claimed that neither he nor Watkins has the team's top end speed.

Tyreek Hill

"I'm not the fastest guy in this locker room," Hill said. "39 is faster than me."

Rookie Tremon Smith wears No. 39 and was drafted in the sixth round out of Central Arkansas. The cornerback ran a 4.38 in the 40 at his pro day.

"The kid got wheels," Hill said.

Smith has taken some of Hill's former special teams duties. He returned three kicks for a total of 75 yards against the Bears on Aug. 25.

So that he could focus on his offensive role, Hill no longer returned kickoffs in 2017 and could have those responsibilities reduced further in 2018. If Hill, who had 1,183 receiving yards last year, didn't call himself the fastest player on the Chiefs, he has to say he's the team's fastest wide receiver, right? Not necessarily.

"Sammy's definitely in the mix," said Hill before slyly looking over at his fellow receivers. "But I feel like Chris Conley is faster than Sammy, though."

Conley, who ran a 4.35 at the 2015 NFL Combine, is coming back from a torn Achilles tendon suffered against the Houston Texans in October last year.

Watkins has fought the injury bug, too. A foot injury ended his 2016 season and limited him to eight games.

But now the challenge for Watkins, who is playing for his third team in just five years in the NFL, is to master Andy Reid's complex offense. He has had to memorize 80 to 90 plays while learning three to four different wide receiver positions so that he can be on the receiving end of Mahomes' passes.

And that can reap benefits. Just ask Hill.

Video of the quarterback's 70-yard bomb to Hill against the Atlanta Falcons on Aug. 17 went viral.

More offensive explosions could be on the horizon for the Chiefs in 2018.

"We've got two of the best deep-ball threat receivers," Hill said. "We will be the best offense in the National Football League."

-- Follow Jeff Fedotin on Twitter @JFedotin.