"They have shown unbelievably poor judgment," Lars Arrhenius, head of anti-bullying group Friends told the Expressen newspaper.
The comments come in reaction to a drill carried out during Tuesday's training session referred to as "the pig" (grisen), a game lost by reserve goalkeeper Johan Wiland.
As "punishment" for losing, Wiland was made to get down on all fours near a wall and pull his pants down, at which point other players fired footballs at the back-up keeper in an attempt to strike his bare bottom (scroll to 1m30s mark of the video below).
While team spokesperson Hans Hultman downplayed the stunt as "no big deal", others were less forgiving in their assessment of scenes featuring players shooting footballs at Wiland's rear end.
"They are heroes for thousands of boys and girls across Sweden and I don't think they should send signals that this is okay," said Arrhenius, whose anti-bullying group's name is set to adorn Sweden's new national arena.
"This is what happens in schools and at sports clubs; that people engage in these sorts of 'games', but there are also children who end up vulnerable in these situations."
A number of politicians also criticized the national team for engaging in what some considered to be "immature" bullying.
"It's tasteless. They're not being good role models," Centre Party leader Annie Lööf told Expressen on Wednesday.
Göran Hägglund, leader of the Christian Democrats said the incidents was "not good".
"Football shouldn't bother with such things. I don't think they should engage in these types of games," he told the paper.
Liberal Party (Folkpartiet) leader Jan Björklund slammed the game as "immature", while Left Party head Jonas Sjöstedt complained that the naked game was "out of place" in 2012.
"It's really sad to see," he told Expressen.
Prime Minister Fredrik Reinfeldt also expressed his concern.
"People who carry expectations should be aware of that and act accordingly," he said.
"It's important to reflect on how what one does in order to meet expectations."
However, Reinfeldt went on to bring the focus back on Sweden's next match in the Euro 2012 football tournament.
"The most important thing for the Swedish people is that we win against England," he told Expressen.
Video footage of the incident from Expressen (in Swedish)