Joe Johnston (left) battles Chase Pami in the 2011 Dave Schultz Memorial International. Both wrestlers are scheduled to compete at the Olympic Trials qualifier on Saturday in Las Vegas. Larry Slater photo.

What happens in Vegas this weekend may have a direct impact on what happens in London next summer.

Plenty will be at stake with many of the nation’s top athletes on display at the Men’s Freestyle Olympic Trials Qualifier, set for Saturday at the Las Vegas Convention Center.

Wrestling is scheduled to begin at 9 a.m. on Saturday with the finals set for 3 p.m. in Las Vegas.

The top three athletes in each of the seven weight classes, who haven’t already qualified, will earn a spot in the field at the 2012 U.S. Olympic Team Trials on April 22-23 at Carver-Hawkeye Arena in Iowa City.

Champions at the Olympic Trials will land a spot at the 2012 Olympic Games in London, England.

The Olympic Trials qualifier will be held alongside the 30th annual Cliff Keen Las Vegas Invitational, one of the nation’s premier college events. Among the top wrestlers expected to compete in the Cliff Keen event is two-time NCAA champion Kyle Dake of Cornell. Dake also is a top freestyle prospect.

With 21 spots up for grabs for the U.S. Olympic Team Trials at this event, the level of competition is expected to be outstanding.

Here is a weight-by-weight breakdown, based on wrestlers who have registered for the freestyle event.

55 kg/121 lbs. –  Past NCAA All-Americans Brandon Precin, Ben Kjar and Mark McKnight are among the wrestlers who have entered in this division.

Precin and Kjar are wrestling freestyle full-time now after completing their college careers this past March.

Kjar lost a close match to 2008 Olympic gold medalist Henry Cejudo in the Sunkist Kids event in October. Cejudo won ball draws in the first and second periods to win the match 1-0, 1-0.

Kjar finished fourth in that event.

60 kg/132 lbs. – This weight class is loaded with wrestlers who have excelled on the collegiate level.

Among the entries in this class are past NCAA All-Americans Andrew Hochstrasser, Daniel Dennis, Dan Mitcheff, Jimmy Kennedy, Tyler Graff and Nick Fanthorpe.

Graff placed third and Kennedy fourth at the Sunkist Kids event. Mitcheff was third at the 2011 U.S. Open. Graff is a past U.S. Junior World Team member.

Veteran Drew Headlee also is entered at 60 kilos. Headlee placed fifth at the U.S. Open this year.

66 kg/145.5 lbs. – 2009 World Team member Dustin Schlatter is the top entry in this weight class.

Schlatter, a past NCAA champion for Minnesota, has dropped down to 66 kilos this season. He won the New York Athletic Club International earlier this month. He already has qualified for the Trials.

Past NCAA All-American Kevin LeValley, another wrestler who has qualified for the Olympic Trials, is expected to compete in Vegas. LeValley placed third at the New York AC event.

2011 Sunkist Kids runner-up Joe Johnston is another wrestler expected to be in contention in this division.

Chase Pami, a past NCAA runner-up, is another tough wrestler in this class. Pami was third at the Sunkist Kids event and fourth at the U.S. Open this year.

Todd Meneely, a two-time NCAA Division II champion, is also looking to land a berth in the Trials. He placed fourth at the Sunkist Kids International.

Past U.S. Junior World Team member Jason Chamberlain could make a big impact in this weight class.

Past Junior Nationals champion Destin McCauley, who has signed with Iowa State, also is entered along with veterans Phil Simpson and Angel Cejudo.

Past NCAA runner-up finishers Joe Slaton and Andrew Long have registered at 66 kilos as well.

Past Cal Poly standout Filip Novachkov is another top wrestler in this weight class.

74 kg/163 lbs. – Past NCAA All-Americans Moza Fay and Tyler Caldwell are among the top competitors expected to wrestle in this division.

Fay placed third and Caldwell fourth at the Sunkist Kids event this season.

Past NCAA All-American Adam Hall is entered in this division. Hall has been wrestling at 66 kilos. Past Ohio State standout Colt Sponseller is another wrestler to watch at 74 kilos.

Andre Metzger, a 1986 World silver medalist and two-time World bronze medalist in freestyle, has registered for this tournament. Metzger, 52, wrestled Greco-Roman at the Sunkist Kids event and went 2-2 in the event.

84 kg/185 lbs. – 2011 NCAA champion Jon Reader is looking to punch his ticket to the Olympic Trials with a strong showing in Vegas.

Reader has placed second in the Sunkist Kids International and third in the Henri Deglane Challenge this season.

Past NCAA champion Max Askren hopes to continue the momentum he has built this season. Askren was second at the New York AC event and third at Sunkist this season. Askren’s older brother, Ben, was a 2008 Olympian.

Past NCAA All-American Doug Umbehauer is another wrestler to keep an eye on in this class. Umbehauer was third at the New York AC International.

Past U.S. National Team member Bryce Hasseman is looking to make a return to Iowa City for the Trials. Hasseman previously trained there. He was fourth at the Sunkist Kids event.

Past NCAA All-Americans Mike Tamillow and Tyrel Todd are among the other top competitors entered in this weight class along with NCAA Division II champion Marty Usman.

Past U.S. National Team member Nik Fekete is entered in this class. Fekete previously competed at 96 kilos, where he placed third in the 2006 World Team Trials and second in the 2008 U.S. Nationals.

96 kg/211.5 lbs. – The battle in this division will come from a list of wrestlers who have earned NCAA All-American honors.

Past NCAA champion David Zabriskie is entered along with past All-Americans Aaron Anspach, Craig Brester, Luke Lofthouse, Mack Lewnes and Trevor Brandvold.

Veteran James Yonushonis also is entered. He placed second in the Hargobind International.

120 kg/264.5 lbs. – Chad Hanke has bumped up to heavyweight this season after turning in a strong finish this past season.

Hanke won University Nationals at 96 kilos earlier this year before placing second at the U.S. World Team Trials.

The Oregon State wrestler is taking an Olympic redshirt this season.