Chris Coleman has urged his Wales team to be "streetwise" and "football smart" if they want to stand a chance of beating Portugal and reaching the final of Euro 2016.
While Coleman's men have won four of their five games in France - losing only to England - Portugal have failed to secure victory in 90 minutes in any of their matches at Euro 2016.
Iceland co-manager Lars Lagerback singled out Cristiano Ronaldo and Pepe for having acting skills good enough for Hollywood before his side's group stage game with Portugal, and Coleman has now told his team to be wary of any unsportsmanlike behaviour on the pitch in Lyon.
"We used to be far too honest, and I'd look at what opposing players used to do to us, and what we'd be doing in the same situations and we'd be miles behind," Coleman said.
"Sometimes it's not pretty, or even ugly, and you can see it as negative. But anything you need to do to stay in the game, do it. It's about being streetwise, and 'football smart'. We've got a lot better at that in the last few years.
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"At this level games are sometimes decided in a split second: with a turnover, the ball changing hands or somebody making the wrong decision and suddenly you're behind in the game.
"You call it gamesmanship but sometimes it's more about being streetwise at this level."
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