Shaqiri drew attention to his heritage last month by posting a photo of his boots, which feature the flags of Switzerland and Kosovo. "We also have to outrun our opponents and I believe also that we have to play our own football".
In the tournament's first come-from-behind victory, Xhaka made it 1-1 in the 52nd minute with a powerful shot through a crowded penalty area, before Shaqiri added the other in the 90th minute after running clear of the Serbian defence.
Shaqiri also played in boots marked with the flags of Switzerland and Kosovo - the breakaway region that is not recognized as independent by Serbia or Russian Federation.
The coach Krstajic is referring to is Vladimir Petkovic, who is hopeful star Valon Behrami is fit to play amid concerns over a thigh problem.
And Serbia head coach Mladen Krstajic is braced for a hard encounter, telling Swiss newspaper Blick: "They are very strong!"
"You should never mix politics and football". "I don't deal with these things". "It's a wonderful atmosphere and a positive experience and that's what football should be about".
Iceland vs Nigeria LIVE on SBS
Moreover, defender Oghenakaro Etebo was unlucky to score an own goal and give Croatia a 1-0 lead in the 15th minute . Iceland are one of the best around at setting up not to be beaten - but they'll need to go out and win this match.
Serbia went in front in the fifth minute when Aleksandar Mitrovic, after missing a header moments earlier, rose above a Swiss defender and wonderfully guided a Dusan Tadic cross from the right past goalkeeper Yann Sommer and into the far corner.
But it was Serbia, who beat Costa Rica 1-0 in their Group E opener, who almost went in two up. Up next for the Swiss are Costa Rica. The Serbia forward amassed four shots against Costa Rica without scoring, having netted five goals in as many global appearances in 2018.
The win puts Switzerland in pole position to make it out of a tough Group E that contains five-times winners Brazil but they were pushed all the way by the Serbs. Mitrovic came close in the 19th minute when he controlled a cross from Branislav Ivanovic on his chest and sent a bicycle kick over the bar.
Shaqiri, Xhaka and Belrami trace their roots to Kosovo, a former province of Serbia, a fact which had stoked tensions before the match. A draw will be enough for Mladen Krstajic's side only if Switzerland lose vs. Costa Rica by two goals.
Brazil, Switzerland and Serbia could all still claim first place in the group with a win on Wednesday.
Shaqiri scored a last-gasp victor against Serbia.