Tim Floyd noted one striking similarity among the teams USC faced in the NCAA tournament last season: Their star players were mostly freshmen and sophomores.

Of course, there was another parallel among Arkansas, Texas and North Carolina: None made it to the Final Four.

But youth will be king regardless of the outcome Thursday evening when sixth-seeded USC plays 11th-seeded Kansas State in a Midwest Regional first-round game in Omaha.

The Wildcats' three leading scorers are freshmen, and yet they might be considered the more veteran team because they feature two senior starters.

The Trojans' starting lineup includes two freshmen and three sophomores, and underclassmen have accounted for 95.7% of USC's scoring, the highest percentage among Division I teams. For all their talent, freshmen O.J. Mayo and Davon Jefferson haven't scored one point in the postseason.

"The NCAA tournament is something new for a lot of us younger guys," Mayo said.

Not every Trojan is a tournament tenderfoot, however. USC has three key players -- sophomores Taj Gibson, Daniel Hackett and Dwight Lewis -- from last year's Sweet 16 run. The returners say they know what it takes to succeed on college basketball's biggest stage.

"We can teach something to the younger guys to let them know what's at stake and how you have to prepare and come ready," Hackett said.

Such as?

"Just take it one game at a time and be patient and every possession counts," he said. "That's going to be key."

Kansas State hasn't been to the NCAA tournament in 12 years. Even though the Wildcats feature singular talents in freshmen Michael Beasley and Bill Walker, Coach Frank Martin acknowledged that his team could be susceptible to big-game jitters.

"Our youth is our biggest strength because it makes us fearless, and it's our biggest weakness because it's the first time we've experienced anything," said Martin, a former assistant under Bob Huggins who took over the program last year after Huggins departed for West Virginia.

"We're so young that the whole stage kind of gets our guys a little nervous. When you're older you tend to handle things a little better."

Gibson said his teammates have all the experience they need after an 18-game slog through Pacific 10 Conference play and two more games in the conference tournament.

"No one's freshmen and sophomores anymore," Gibson said. "These guys are getting ready to be sophomores and juniors. Guys are grown, and we're not your average young team. It shouldn't affect us come late March."

USC Coach Tim Floyd said it seemed as if his team had been playing in big games for the last two months after opening Pac-10 play with three consecutive losses. The Trojans responded by winning 12 of their last 17 games, including victories over UCLA and Stanford.

No opponent should intimidate USC considering the Trojans have already played three top-seeded NCAA tournament teams (UCLA, Memphis and Kansas) and one third-seeded team (Stanford).

"For a young team to go into some of the buildings we've been in and play and have 96% of our scoring from freshmen and sophomores is a tribute to their talent," Floyd said. "They have great talent and they have great heart and have been a very good defensive team all year."

Kansas State has played a difficult schedule as well, with games against Kansas, Notre Dame, Texas and Oklahoma. The Wildcats split two games with the Jayhawks, beat the Sooners and lost to the Fighting Irish and the Longhorns.

"They're a talented team that probably should have gotten a higher seed," Gibson said. "Not many teams can say they beat Kansas."

Mayo repeated his contention that USC is a national-title contender despite its inexperience and the fact that it finished tied for third in the Pac-10 before losing in a conference tournament semifinal.

"We feel like we were in there with three of the top teams in the country in Memphis, Kansas and we beat UCLA at UCLA," Mayo said. "From that standpoint we feel like we can play with anyone and we're just going to continue to get better."

Martin pondered his team's matchup with USC and said he noticed several similarities. Each team has six freshmen, and the Wildcats have eight first-year players.

"They're led by two freshmen just like we're led by two freshmen," Martin said. "We've got two senior guards and that's kind of where our upperclassmen stop. Everyone else is either a first-year guy or a sophomore who didn't play last year as a freshman.

"Everything is going to be a first for all our guys."

ben.bolch@latimes.com