Who will make the women’s gymnastics team? Fourth-Place Medal preview with Shannon Miller

The U.S. Olympic Gymnastics Trials start Thursday in San Jose, Calif., with the first day of men's competition. On Friday, the women will compete, starting the process of weeding down 12 Olympic hopefuls into five Olympians.

"As an athlete in the United States, the Olympic trials are much more difficult and much more pressure-packed than even the Olympic Games," Shannon Miller, the most decorated American gymnast and Yahoo! Sports commentator, told Fourth-Place Medal.

"To get on this team, with only five positions, is extremely difficult. You have to peak a little there, or you won't make it on the team, and you have to really peak at the Olympics."

The United States women won the world championship in 2011, and individual gold in the all-around (Jordyn Wieber) and vault (McKayla Maroney). The expectations are high for the U.S. to win gold in London, and the selection committee will have to put together five athletes who will provide consistent scores.

Miller talked about the gymnasts who barring a disaster this weekend are locks, and who is sitting on the bubble.

[ Related: Maroney makes it back after frightening recent fall ]

"Jordyn has shown amazing consistency," Miller said about Wieber, the defending world all-around champion. "She just wins meet after meet after meet. Even when she does have a minor mistake, she's such a fighter, she fights for those tenths of points.

"Gabby Douglas is just a changed athlete. If you go back and watch last year's national championships, on balance beam, it was a disaster. She was able to be on the world championships team that won the gold medal, and it changed her entire perspective of who she is as an athlete. It made her so confident. She continues to have little issues on balance beam, but the Gabby Douglas who hits on beam could win a medal on the all-around at the Olympics.

"Ally Raisman understands her position. Her position is to be the consistent go-girl. You need someone to hit a solid routine? Not going to be flashy. Not going to be that exciting, but she's going to hit it and hit it cold. It helps anchor the team.

"Kyla Ross really made a statement," Miller said about Ross, who will 16 in October. "She goes out there and does her job. She's got that international look. She doesn't cave under pressure."

[ Photos: American gymnast Jordyn Wieber ]

Under the current system, each Olympic team is allowed five spots, but picking the team isn't as simple as choosing the top-five all-around scores. At the Olympics team competition, three gymnasts per team perform on each apparatus, and every score counts. In previous games, the lowest score was dropped. This scoring scenario means the selection committee may pick an athlete who can post a big score on one event as long as her teammates can pick up slack on the other events.

"For these girls who are on the bubble and aren't performing the all-around, they can't just perform those events. They have to be first or second in those events. They have to be head and shoulders above the crowd," Miller said.

Two of those bubble athletes are Nastia Liukin, who won gold in the all-around in Beijing, and Alicia Sacramone, who won team silver in 2008.

"Nastia has a tough road ahead. With balance beam, she does a great job. She's consistently in the top five, but it's not enough, because she doesn't do floor. She doesn't do vault. Bars? We didn't see her hit a set [since she's come back], and you can't go into the Olympic Games and not know if someone is going to hit a set. She's in a difficult position.

"Alicia is in a really tough position. She's made an incredible comeback and she's a leader for this team. Every one of the girls talks about what a leader she is. Because she's competing beam and vault, two events that we're really strong in, it's going to be really difficult for her to make the team. I think she understands that."

Another bubble athlete is McKayla Maroney, who was injured during Visa Championships in early June, but will compete this weekend and has a monster vault. After Visas, Miller made her picks for the team, with the caveat that trials can change things quickly.

"If I had to pick the top four, Wieber, Ross, Douglas, Raisman. Then you have to look at who is the fifth athlete, and you have to look at McKayla Maroney because of that huge vault score and the fact she can perform on four events. Sarah Finnegan, if she does an incredible job at trials. She could be in there. You look at Rebecca Bross or Nastia Liukin, if you're looking for just a bars score."

With so many tough athletes and just five spots, this weekend should provide plenty of interesting twists and turns, both in and out of competition.

More Olympic coverage on the Yahoo! network:
How Mary Lou Retton captured America's heart
Raising an Olympian: Alicia Sacramone
Nadia Comaneci vied for perfection in 1976