Actually, Seger said in an interview that it's 100% sure that Streit will be the Captain for the Olympics. Kind of funny how that worked out. Probably Simpsons choice and so Seger didn't think it had much sense argueing. It's just a letter on the jersey and Seger and Streit will possibly share the role in the locker room.
Here is the interview between TagesAnzeiger and Seger with
translation:
TA: Wären Sie gerne wieder Captain an den Olympischen Spielen?
Would you like to be Captain at the Olympics?
Seger: In Sotschi ist Mark Streit Captain. Ich wäre einfach gerne dort dabei.
In Sotschi Mark Streit is going to be Captain. I'd just like to be there.
TA:Steht das fest mit Streit?
Is it definitive that Streit will be captain?
Seger: Es ist für jeden Spieler klar, dass Streit der Captain sein wird.
It's clear for every player that Streit is going to be the captain.
TA: Nationalcoach Sean Simpson hat das aber noch nicht gesagt, oder?
But coach Sean Simpson hasn't already said so, or did he?
Seger: Das muss er nicht sagen. Das ist klar. Weil Streit schon immer Captain war. Und weil er unser bester Verteidiger ist.
He doesn't need to. It's clear. Because Streit has always been our captain. And because he's our best defensemen.
Ta: Aber Sie sind der Silbercaptain.
But you are the captain that lead the team during the silver run.
Seger: Ja, das ist schön und gut. Aber es ist Streits Position. Ich durfte einspringen, weil er nicht kommen konnte.
Yeah, that was great. Still, it's Streits position. I was captain because he couldn't be there
Source:
http://www.tagesanzeiger.ch/sport/fussball/Die-Guetsli-meiner-Mutter-sind-ein-Gedicht/story/16291040.