At the London Olympics, Russia finished second to the U.S. in the track and field medal standings.

With Russia unable to send a track and field team to Rio, top rivals to U.S. Olympic medal hopefuls may be absent from the Games in August.

The IAAF left “a very tiny crack in the door” for Russian athletes to apply to compete in Rio independently, should they prove to have been subjected to reliable drug testing outside of the Russian regime.

Until then, these 10 Americans’ medal hopes were boosted with Friday’s announcement:

Jenn Suhr, Pole Vault

Russia’s biggest track and field star is 2004 and 2008 Olympic pole vault champion Yelena Isinbayeva. In 2012, Suhr relegated Isinbayeva to bronze in London.

Isinbayeva came back to win the 2013 World Championship over Suhr and then took off all of 2014 and 2015 due to pregnancy. Isinbayeva’s comeback this year (she can compete domestically but not internationally) has been slowed by injury, but will sue after Friday’s IAAF ruling.

Suhr lobbied Thursday for Isinbayeva to be allowed to compete in Rio.

Suhr cleared an indoor world record of 5.03 meters on Jan. 30, the best mark indoors or outdoors in the world since Isinbayeva’s last outdoor world record of 5.06 in 2009.

Vashti Cunningham, High Jump

In no track and field event is Russia deeper than women’s high jump. Russians earned two medals each at the 2012 Olympics, 2013 World Championships and 2015 World Championships, including golds at all three from Anna Chicherova, Svetlana Shkolina and Mariya Kuchina.

Last year, seven of the world’s nine clearances of 2.00 meters or higher came from Chicherova and Kuchina.

Take all the Russians out, and the women’s high jump field in Rio is wide open. There are the veterans — led by Ruth Beitia, 37, of Spain and Blanka Vlasic, 32, of Croatia — and the newcomers such as Vashti Cunningham, the World Indoor champion and daughter of retired NFL All-Pro quarterback Randall Cunningham.

Cunningham has yet to replicate her indoor success in outdoor meets this spring, ranking seventh in the world.

Erik Kynard, High Jump

Russia actually swept the 2012 Olympic high jump titles, with Ivan Ukhov taking gold over Kynard.

Neither Ukhov nor Kynard made the podium at the 2013 Worlds (Ukhov fourth, Kynard fifth) or 2015 Worlds (Kynard eighth, Ukhov failing to make the final). Another Russian, Daniil Tsyplakov, placed fifth in 2015, though.

The Olympic high jump gold-medal favorite, regardless of Russia participation, appears to be Qatar’s Mutaz Barshim.

Alysia Montaño and Ajee’ Wilson, 800m

Russia took gold and bronze in the 2012 Olympic 800m, with both runners (Mariya Savinova and Ekaterina Poistogova) being implicated in doping reports as far back as December 2014.

Savinova and Poistogova were likely to miss Rio regardless of Friday’s ruling, as both were recommended last year to serve life bans by the World Anti-Doping Agency.

But Russia has long been strong in the women’s 800m, and other medal threats could have emerged. Without Russia, South African Caster Semenya is an even bigger gold-medal favorite. Burundi’s Francine Niyonsaba is in solid silver-medal-favorite position.

After that, Montaño and Wilson are medal threats if they make the Rio team by finishing in the top three at the Olympic Trials on July 4.

Montaño was fifth at the 2012 Olympics and fourth at the 2013 World Championships. Wilson ran the fastest time in the world for 2014.

Aries Merritt and David Oliver, 110m Hurdles

Merritt is the reigning Olympic champion and world-record holder. Oliver took the 2013 World title. But Russian Sergey Shubenkov is the reigning World 110m hurdles champion, beating both Americans last year.

Shubenkov was eliminated in the first round at 2011 Worlds, then the semifinals of the 2012 Olympics before winning bronze at the 2013 Worlds behind Oliver.

Shubenkov captured the 2015 World title in a national-record 12.98 seconds on Aug. 28, but his best time in three domestic races this year has been merely 13.24, according to Tilastopaja.org. He clocked 13.41 in his most recent race June 4.

Merritt, who is coming off a Sept. 1 kidney transplant and a follow-up surgery more than one month later, also has a best time of 13.24 this year. Oliver is the fastest American this year at 13.09.

But everyone is looking up at Jamaican Omar McLeod, who has the four best times in the world this year, including a 12.98.

Johnny Dutch, 400m Hurdles

Dutch, a part-time filmmaker, is a 27-year-old veteran who has never made an Olympic team nor a World Championships final in two tries in 2009 and 2015.

But he is looking like the Rio Olympic favorite, with the two fastest times in the world this year at 48.10 and 48.36 seconds. Next fastest? 48.67 seconds.

His chances would be boosted slightly by the absence of Russian Denis Kudryavtsev from Rio. Kudryavtsev emerged last year to take silver at the World Championships in a national record 48.05 seconds.

Plus, surprise World champion Nicholas Bett of Kenya has struggled mightily so far this year. The U.S. swept the 400m hurdles at the 2008 Beijing Games and may have a great shot to do so again in Rio.

Brittney Reese and Tianna Bartoletta, Long Jump

The U.S. is home to the reigning Olympic champion (Reese) and World champion (Bartoletta) in the long jump, but Russia has been producing world-class jumpers en masse for several years.

From 2009 to 2015, a different Russian woman ranked in the top six in the world every year. Some Russians showed up multiple times, but there was at least one new one every year.

However, the best Russian woman this year, using results from small, domestic competitions, would not rank in the world top 10. Bartoletta, who won her two World titles 10 years apart, has struggled, too, ranking fifth among Americans.