FC Barcelona defender Javier Mascherano says that because of the referee leniency, his Argentina teammate Lionel Messi is struggling to stand out in the Copa America.
Read: "Messi Will Not Leave Barca"
The defender admitted that in South America, or the Copa America, the referees allow tougher challenges, which makes it more difficult more Messi to stand out.
"When he plays it's almost normal that he is the Man of the Match," he told Gazzetta dello Sport.
"He's in great form and has so much desire to do well in a tournament that is not easy to win.
"Here, the referees are lenient.
"The challenges and the contact are greater.
"So it's tough to still stand out the way Leo does - more so than in Europe."
Mascherano insisted that it's difficult for star players to shine on the South American continent, but said that Argentina must stay strong, and fight to win.
"South American football is difficult. We know that from the World Cup qualifiers and the Copa reflects that," he continued.
"Even if you have great players, it's never easy to make the difference.
"For our part, we just want to maintain our style, try to play football, but we must be clear in our heads that when we have to fight, we will do so."
The 31-years-old Mascherano has played 111 times for his country since his debut in 2003, scoring three times from defensive midfield and centre-back.
Read: 'Ronaldo Must Step Aside Sometimes For James'
Messi is yet to win major silverware with his country, but came close last year when Argentine lost to Germany in the 2014 World Cup final.
Why do you think Lionel Messi has never replicated his club form on the international stage? Let us know in the comments section below.
