The United States women's national team typically has the same turnover rate as a department of tenured university professors.

Of the 28 players who have seen action for the USA in 2013, 12 have 50 or more caps. The United States men's team in the same period has used 47 players, only eight of whom have 50 or more caps. And the men have played meaningful competition such as World Cup qualifiers and the CONCACAF Gold Cup , where experience can help.

The women's team has a rare chance to see some new talent in Washington's RFK Stadium in a friendly against Mexico ( live, FOX Sports 1, Tuesday, 8 p.m. ET ). New coach Tom Sermanni has already given seven players their international debut in his year in charge. Three of them -- Morgan Brian, Crystal Dunn and Kristie Mewis -- are on the roster for the Mexico game along with an uncapped trio -- Leigh Ann Robinson, Erika Tymrak and Vanessa DiBernardo.

"We have got three players in the 18 who haven't been in the national team squad yet, and we've got a couple of other young ones who have come in who haven't been in the squad for long," Sermanni said. "So when you look at the squad, there's actually 30 percent of the squad who are either completely new or only recent additions to the squad. That's reasonable turnover, particularly for a successful squad."

But the roster also includes all the usual suspects: Hope Solo (137 caps), Rachel Buehler (103), Heather O'Reilly (188), Carli Lloyd (157), Lauren (Cheney) Holiday (90), Abby Wambach (207) and the ageless Christie Rampone (283). Even Alex Morgan (68), who played as a substitute in the NWSL final with a knee brace, is in Washington. Some of the other veterans of recent major tournaments are injured (Shannon Boxx, Megan Rapinoe) or busy overseas (Tobin Heath, Ali Krieger).

The most puzzling aspect of the Mexico roster on the surface is the lack of players breaking through from the NWSL; Brian, Dunn and DiBernardo are still in college; Mewis was already on the radar before the season, leaving only her FC Kansas City teammates Tymrak and Robinson as players who earned a shot through pro play.

Why is it so hard to break into this exclusive club? A few factors:

1. No global talent pool: The US men frequently audition young players from Europe and elsewhere who have dual citizenship. In the women's game, only the best and most experienced players would break into the US player pool, and it's a little late to switch Diana Matheson's nationality from Canada or lure Ali Riley from New Zealand. One rare exception is Sydney Leroux, who played in the Canadian youth system but chose to play for the United States -- and Canada won't let her forget their frustration.

2. Veterans want to play whenever possible: Men's players would burn out if they played every available club game and international game. Not in the women's game, where the club seasons aren't as long -- if they even exist, which hasn't consistently been the case for many players over the past decade.

"The veterans don't want rest," Sermanni said. "They haven't played for the national team since the middle of June."

3. Marketing: Hundreds of fans turned out in the sweltering heat of RFK Stadium to watch the team go through an open practice, and as usual, many of them had signs and jerseys for their favorite players' autographs.

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4. The style of play isn't changing much : Even with Sermanni replacing Pia Sundhage, the players who were comfortable in Sundhage's system are comfortable today.

"Philosophically, Pia and myself have got similar ideas about how we want to play the game," Sermanni said. "You're going to win games, so you want to play an attacking brand of football. We have just some slight difference in how we're going to do that. Pia had a tendency to have her wide players really wide. I tend to have players play a bit closer together. And we try to vary the tempo so we're not always playing 100 miles per hour. But it's not like I've come here and said, 'We're making massive changes.'"

New players, such as NWSL Rookie of the Year Erika Tymrak, are the ones making the adjustment.

"I don't know if my style of play is always favored," Tymrak said. "I like going at people and trying to do things. Playing with this team, I'm going to play more simple but try to be myself at the same time."

5. The players aren't aging or falling out of form: The national teamers had solid and occasionally spectacular NWSL seasons. Holiday and Wambach finished 1-2 in MVP voting. FC Kansas City's Becky Sauerbrunn and Rampone finished 1-2 for Defender of the Year, with new call-up Robinson third. Backup goalkeeper Nicole Barnhart was Goalkeeper of the Year. That group, along with Leroux, made the Best XI.

The buzz at practice was around Brian, a Virginia junior who impressed Sermanni and teammates with her confidence when she started coming to national team camps.

"Not a lot of things make me nervous or anything like that," Brian said. "I'm pretty comfortable playing with these players, and they made me feel comfortable as well."

The highlight of Monday's practice was a 30-yard shot from Yael Averbuch that zipped over Hope Solo's hand into the net, drawing gasps from a crowd that had been quiet to that point. Averbuch, the only player based in Europe on the roster for the Mexico game, has collected 23 caps over a seven-year span -- a rare example of a veteran player getting multiple looks with the team.

Even Sauerbrunn, a defender with 44 caps who has several inexperienced Kansas City teammates joining her at camp, feels like a newbie at times.

"I have been teasing (my K.C. teammates) saying there are rookie initiations they have to do," Sauerbrunn said. "But there's nothing. They're going to be completely fine.

"I've been thinking maybe we should start that, but I don't know if I'd retroactively have to do that at some point."