Sarah Sjöström was one of this country's brightest medal hopes, but only finished fourth in the swimming 100 metre butterfly final on Sunday evening.
"I was surprised that it went so slowly," she told Swedish Radio Sport after the race. "It had felt good ahead of the race. But during the last quarter of the race, I was completely exhausted."
And, to make matters worse, Sjöström lost her three year old world record in the event to the American swimmer Dana Wollmer.
The Swedish team's troubles began on Friday last week, when veteran Therese Alshammar announced that she would skip the 100 metre freestyle and bet it all on the 50-metre swimming event.
On Saturday, cyclist Emma Johansson, who won a silver medal in Beijing in 2008, finished sixth in the women's time trial race.
"I am very disappointed," Johansson said, "We were racing for the gold but ended up sixth. We did what we could, but sometimes that does not get you all the way."
Among the other Swedish failures was the table tennis player Jörgen Persson, who is competing in his seventh Olympics but has yet to earn a medal.
He was knocked out of the second round Sunday in straight sets by Croatia's Andrey Gachina.
"I struggled to get into the game, and when I did I made simple mistakes," Persson told Swedish Radio.
At the 1908 and 1948 London Olympics, Sweden averaged 35 medals. But, at the present rate, the grand total this time around will be what it was in Athens in 1896: that is, zero.
But things may be looking up.
Swimmer Therese Alshammar could still be fit for the 50 metre freestyle and Sarah Sjöström, who missed the podium Sunday night, woke up this morning and made it through the trials in the 200 metre freestyle. That semi-final is tonight.
Podium miss devastates swimmer Sjöström
Sarah Sjöström, one of Sweden's major medal hopes going into the Olympics, came in a disappointing fourth in the women's swimming 100-metre butterfly event on Sunday.
She also lost her three year old world record.