Kansas City head coach Andy Reid is wary of a San Francisco sting, warning the 49ers are even better than the team the Chiefs beat four years ago in the Super Bowl.

The Chiefs ended their 50-year wait for Super Bowl success with a 31-20 victory over the 49ers at Miami's Hard Rock Stadium in 2020, despite trailing by 10 points going into the fourth quarter.

Reid's team have enjoyed a spell of dominance since, with Sunday's clash (Monday AEDT) in Las Vegas their fourth Super Bowl appearance in the last five seasons.

But the veteran coach says the addition of star running back Christian McCaffrey and the emergence of quarterback Brock Purdy's have made Kyle Shanahan's side even stronger.

"The 49ers have an offence that has a lot of talent, a lot of guys that can do a lot of things," Reid said.

"There are quite a few of the same guys (from 2020) and they played to a very high level then. They are even better now.

"McCaffrey would be new, he's a pretty big ingredient. The quarterback (Purdy) is new and he's a heck of a football player.

"The rest of the surrounding cast is similar to what they had before."

While the Chiefs are trying to become the first NFL team to win back-to-back Super Bowls since the New England Patriots in February 2005, it has not been a smooth path to the showpiece.

Kansas City suffered four defeats in six towards the end of the regular season, but found form in the play-offs.

Reid credited their turnaround to a mixture of fun and focus.

"We try to have fun within the intensity of the game," he said.

"During the week there is a time to focus in, a time to mess around.

"They know the drill, they know when they can focus and need to focus.

"And then they can also know when they can mess around, goof around with each other and let their personalities show."

This week, star Chiefs defensive lineman Chris Jones said his side were the "villains" in the eyes of many NFL fans.

Quarterback Mahomes is fine with that if it means he wins a third Super Bowl ring.

"I just like winning," the two-time Super Bowl MVP said.

"If you win a lot and it causes you to be a villain, I am OK with it.

"I will enjoy playing the game and try to win as much as possible."