Here’s a preview of swimming races today.

TOKYO — Swimming today (Saturday morning in Tokyo, Friday night in the U.S.) presents the second-to-last day of the competition, the last race for Katie Ledecky and another chance for Caeleb Dressel to win gold.

The United States has 24 medals, 10 more than any other country. (That would be Australia, with 14, followed by Britain, with six.) If there is disappointment among Americans, it is that they are showing depth more than dominance. Only — only being relative — six of the 24 medals are gold.

The session will have four finals, including three in a row to start: men’s 100-meter butterfly, women’s 200 backstroke and women’s 800 freestyle. That is the one that Ledecky will swim, looking to add to her Tokyo haul of a gold medal and two silvers. She is heavily favored to win gold here, but Ariarne Titmus of Australia has been a threat in other races.

Dressel could win his third gold medal of these Olympics. He holds the world record (49.5, in 2019) and the Olympic record (49.71, Friday), and no one else in the field went below 50 seconds in their heats.

And two Americans could boost the medal haul in the women’s 200 backstroke. The biggest question is what color the medals will be.

The final event is the mixed 4×100 medley, the first mixed-gender swimming race at the Olympics.

On Friday, American Ryan Murphy added further intrigue to the final days of the meet by mentioning the “d” word (doping) after finishing second to a Russian in one race and two Russians in another. Russian athletes are allowed to compete if they meet antidoping protocols laid out by meet organizers.

“I try not to get caught up in that,” he said, without directly accusing the winners of cheating. “It is a huge mental drain on me to go throughout the year knowing that I’m in a race that probably isn’t clean.”

The Russian Olympic Committee (going by ROC at these Games) responded on Twitter as if swimming had entered a cold war in the water.

“How unnerving our victories are for some of our colleagues,” it said, in Russian. “Yes, we are here at the Olympics, whether someone likes it or not.”

It showed photographs of three athletes who have openly, but not harshly, questioned Russia’s presence here — Murphy, British swimmer Luke Greenback, and American rower Megan Kalmoe — and called it “English-language propaganda” from “athletes offended by defeats.”