PORTO ALEGRE, Brazil, June 22 (Xinhua) -- Qatar head coach Felix Sanchez vowed that his players would not be star-struck by Argentina captain Lionel Messi when the teams meet in their final Copa America Group B match here on Sunday.

Both teams have just one point from their first two matches and need to win at Arena do Gremio to progress to the next stage of the tournament.

"It's true we are not very well known in South America but we have super-professional players and we've come to compete, not to take photos with Messi," Sanchez told reporters on Saturday.

"They're the favourites and are obliged to win. We'll try to compete against a great team who have the best player in the world. We have a chance to qualify and that's what's exciting, not the fact we could knock out a monster like Argentina."

Messi, who returned to Argentina's national team in March after a self-imposed eight month exile from international football, has scored the Albiceleste's only goal of the tournament so far - a penalty in last Wednesday's 1-1 draw with Paraguay.

The Barcelona forward is still striving for his first major trophy with Argentina's senior national team, whose title drought dates back to 1993.

Sanchez, a former Barcelona youth team coach, said that no amount of planning could counter Messi when the 31-year-old is in top form.

"He can be decisive in any game due to his quality," the 43-year-old Spaniard said. "Hundreds of coaches have spent ages trying to stop him but there's no magic formula, it all depends on Leo's feet.

"However much you focus on it it's very difficult to stop him, but we'll try to prevent him from getting involved in the play in the final third of the pitch."