Angel di Maria has sent a warning to the rest of the countries still in the World Cup - Argentina still have room to improve.
The two-time winners won all three of their group games, but owe that largely to the excellence of Lionel Messi.
Argentina stuttered to victories over Bosnia-Herzegovina and Iran but showed signs of improvements against Nigeria in a 3-2 victory, but still showed defensive frailties.
Di Maria is quoted in Madrid based magazine Marca saying "we go from strength to strength."
And sent the stark warning to their opposition "we have not reached our best level yet."
At 26-years-old di Maria has developed into a vital player for both Real Madrid and Argentina and is aware of how a slip up could cost his side at this years World Cup, "we should be focussed on not making any mistakes because if you lose at this you're out."
Argentina face Switzerland in the last 16 and di Maria is aware of the attacking potential the Swiss side have.
He said: "They have good midfielders and forwards, but not as solid in defence."
Adding "it will be a more open game, like the Nigeria match."
Swiss were goal-happy
Switzerland scored an impressive seven goals during the group stages, but their defensive difficulties where highlighted by France who managed to put five past them.
Di Maria will be hoping to take advantage in the gaps in the Swiss defence after failing to score yet, despite 3 attempts against Nigeria.
The midfielder starred for Real Madrid in the second half of last season and will be hoping to transfer his club form to the knockout stages of the World Cup.
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