Portuguese duo Ricardo Quaresma and Miguel Lopes were involved in a training ground bust-up ahead of their Euro 2012 semifinal.

Tension is mounting in the Portugal camp with four days to go before they face Spain or France for a place in the European Championship final.

During one drill, winger Quaresma was pushed to the ground by Lopes and had to be pulled back by teammates when he retaliated by kicking at the defender's legs.

Defender Ricardo Costa stood in front of Quaresma to calm him down while coach Paulo Bento also got involved.

"It's just normal things that happen in training," Costa said.

"Things got a bit heated between two players. We're pumped up, we always want to win and sometimes small things happen.

"Everything's sorted now. We all want to play in the semifinal and sometimes stuff happens."