By Chrös McDougall | Oct. 21, 2015, 4:06 p.m. (ET)
Top row: (L-R) Brandon Wynn, Danell Leyva, Donnell Whittenburg; bottom row (L-R) Chris Brooks, Paul Ruggeri, Alexander Naddour, Marvin Kimble

It’s next man up for the U.S. men’s gymnastics team.

With Sam Mikulak, the three-time defending U.S. all-around champion, out of the FIG World Artistic Gymnastics Championships, everyone must step up.

Losing Mikulak, a 2012 Olympian who injured his left ankle in training earlier this month, is certainly a blow for a team looking to medal at a third consecutive world championships, which runs Oct. 23-Nov. 1 in Glasgow.

Yet in Mikulak’s absence comes opportunity.

Chris Brooks and Marvin Kimble, originally listed as alternates, are traveling with the team to Glasgow. The six-man squad and one alternate will be determined before the team begins the qualifying round on Monday.

Of the group previously selected for the U.S. team, three of the six gymnasts who combined for the team bronze medal last year are back, including two — Donnell Whittenburg and Danell Leyva — with something to prove.

Levya is the talented veteran and former parallel bars world champion who has struggled to rediscover the form that led him to an Olympic all-around bronze medal in 2012. Whittenburg, meanwhile, is the up-and-comer who teased a breakout at last year’s world championships and solidified his résumé at this summer’s U.S. championships.

Joining them from last year’s team is pommel horse specialist Alexander Naddour. Rings specialist Brandon Wynn and three-time world championships alternate Paul Ruggeri make up the rest of the squad.

Winning a third consecutive world team medal — something the U.S. men have never done before — will already be difficult. China has dominated the world championships since 1994, winning all but one gold medal. The Chinese also won three of the five Olympic team gold medals in that time.

Meanwhile, Japan, team silver medalists in the past four world championships and two Olympic Games, brings back reigning Olympic and five-time all-around champion Kohei Uchimura, considered by many to be the best men’s gymnast of all time. The hosts, Great Britain, have been on the rise as well.

Losing Mikulak hurts, but the veteran U.S. squad now has an opportunity to show their savvy less than one year before the Rio de Janeiro 2016 Olympic Games begin. Here’s a look at the seven gymnasts looking to make their mark.

At the world championships, each team has six gymnasts. Five compete in each event during the qualifying rounds with the top four scores counting; three compete and three scores count in each event for the team finals. Meanwhile, from qualifying, the top eight teams make the team final, and the top 24 all-arounders and top eight in each event move onto those finals, though only two per country can advance in each final.

Chris Brooks
Age: 28
Hometown: Houston
How He Can Help: His window of opportunity appeared to close after serving as an alternate at the 2012 Olympic Games, but Brooks found new life and had his best showing at the U.S. championships this summer when he was first in high bar, second in parallel bars and third in all-around.

Marvin Kimble
Age: 19
Hometown: Milwaukee
How He Can Help: A rising star in the U.S. program, Kimble was fifth in the all-around at this summer’s U.S. championships, shortly after tying for first in pommel horse at the Pan American Games. Dominant on the junior level, Kimble won the all-around and four events at his last junior U.S. championships in 2012.

Danell Leyva
Age: 23
Hometown: Miami
How He Can Help: Though the most accomplished gymnast on the team, Leyva has been inconsistent after winning the 2012 Olympic all-around bronze medal. Since then he hasn’t finished higher than fifth in the all-around at the U.S. championships. However, his talent is clear, and he has two world medals in parallel bars (gold – 2011, silver – 2014) and is world class in high bar.

Alexander Naddour
Age: 24
Hometown: Gilbert, Arizona
How He Can Help: Naddour consistently stands out in the U.S. men’s worst event: pommel horse. He’s won four of the past five U.S. pommel horse titles and was runner-up the other year. The 2012 Olympic alternate, Naddour placed sixth in pommel horse at last year’s worlds. He’s also had success on rings.

Paul Ruggeri
Age: 26
Hometown: Manlius, New York
How He Can Help: The longtime U.S. national team member will make his world championships debut in Glasgow after having been an alternate three times. Ruggeri has shown flashes of potential for moving into the top group of U.S. all-arounders, and he’s strong in floor exercise, high bar and vault.

Donnell Whittenburg
Age: 21
Hometown: Baltimore
How He Can Help: After posting the fourth-best all-around qualifying score at last year’s world championships, Whittenburg slipped to 17th in the final. With Mikulak out, Whittenburg, the 2015 U.S. all-around runner-up, has the spotlight. He could also factor individually, particularly in parallel bars and still rings. The powerful gymnast shines on floor exercise and vault as well.

Brandon Wynn
Age: 26
Hometown: Voorhees, New Jersey
How He Can Help: The U.S. men’s resident still rings expert is still going strong. Since 2010, Wynn has won four U.S. titles in the event and was runner-up the other two years. At his last world championships, in 2013, Wynn won a bronze medal on the event and made the parallel bars final.

Chrös McDougall has been a reporter and editor for since 2009 on behalf of Red Line Editorial, Inc. He is based in Minneapolis-St. Paul.