Depends on what country. Russia, China and Czech Republic are pretty cut throut with there 5th men and they will swap players during games if they are not playing well. Probably because they are new to the game and dont have the traditions that the other countries have like Canada, USA and the european countries have, who all that barely use them. Except Scotland.

Hello Dunoonrock

I am not in Vancouver, but I tried to get my hands on the few news that get across to here. Slight correction, skip is Bärtschiger with the Swiss team, would be surprised if Pätz got in as well. From what I heard, Baertschiger didn't perform to his standards so they got Meier in as skip. It may be surprising to see the alternate being brought in to skip, but let me explain. Up until two years ago, (when the national champ 08 would represent Switzerland at the worlds 09) the alternate of the Swiss teams at junior championships normally was the skip of the runner-up - this was intented to give the skip international experience prior to his first "serious" try on that level. While this practice has loosened, it is still common to take a skip of the runner-up (or some other team) with you, so as to have a back-end player at hand if necessary. Meier has probably been the (technically) best skip for the last two years, but he has an inexperienced front-end and only made the semi-final in the swiss champs this year.

As to the general situation: The tendency in Switzerland really seems to move towards the fifth player being there to cover for illness or if a player is performing badly. That being said, I cannot remember an incident where the skip was relegated to the bench / removed from his skipping position (which is not the same as throwing last rocks as others have already pointed out!). My brother recently was at the EYOF with the Swiss junior boys team. The national coach apparentely didn't want to give the fifth player a game (because according to him there was no reason to take out one of the others), so in the end the team actually stood together and forced a change through and the alternate got a game in the round robin. And that's also the way it's supposed to be I reckon.

Yes, I know about "never change a winning team" etc. but I also strongly believe, if you have somebody take three weeks off and come along to an international competition as the alternate, it is only fair and decent to give him or her one game. I'm not saying that player has to play in the back-end, but in my book, if you put in that kind of commitment to accompany a team (especially if it's not your normal team), then you have earned the right to wear your country's colours on the ice.
I believe there used to be a rule at the olympics which said that spare players only get a medal if they have played at least once during the tournament. I don't know wether that rule still applies, but to me it would make sense. It's all about fairness in my book...