Switzerland have not made the World Cup quarter-finals since they were the host nation 68 years ago, although there was no round-of-16 in that era.
The Swiss went out in the first knockout stage in each of the last two World Cups but Yakin says the prospect of taking on Portugal should be motivation enough for his side.
"We are aware that we are going into the game with a team that is well-prepared, that is mature," he said.
"Being able to write history will not be decisive for us. We know our opponents and have shown that we can beat them. Then maybe we can discuss the history.
"You can't focus on what happened in sport. No one cares what happened anymore. Of course, expectations are growing but we fight with the players I have and the opportunities we have."
Yakin said he has his entire squad available for selection but gave no clues as to his starting line-up.
"We are ready. We have a full squad, the players who were missing are back on board. We look forward to the game. It's a great opportunity to continue writing history. We are aware of the euphoria in Switzerland and want to give everyone another game."
Switzerland beat Portugal 1-0 in Geneva in the Nations League in June, a week after crashing to a 4-0 loss in Lisbon but Yakin said those games count for little.
"It's been six months since the last contest and that's a very long time in football. We don't know who plays for them, who plays in central defence. If we focus too much on the opponent, we lose sight of ourselves," he added.
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