Goncalves is being helped to prepare the team by a psychologist

Laurindo Vieira will help prepare the Palancas Negras for Friday's World Cup Group D game with Mexico.

Vieira lectures at Luanda's prestigious Catholic University and is expected to give the team mental strength.

"The psychologist will talk to them about confidence and improving their mental strength," team spokesman Arlindo Macedo said.

Vieira was brought in after Angola's poor performance in the African Nations Cup in January, which also cast doubt on the position of coach Luis Oliveira Goncalves.

Instead of dismissing Goncalves, the technical team decided to strengthen the coaching staff, with Goncalves asking for a psychologist and statistician.

"The psychologist talks to them about brains and nerves and he tries to make them more confident in themselves and in the team," Macedo said.

"I'm not really sure what they do in these lectures but the players come out laughing about who is using the right side of their brain and who is not."

Whether the psychologist has any effect against Mexico remains to be seen but Goncalves is not only relying on mind games.

"The squad have been watching videos of Mexico's matches," he said.

"They've seen a few games already but once more is never too much.

"Each one will know who to mark and what to watch out for."

Macedo said the mood in the camp was upbeat, with the side ready to go all out for victory in Hanover.

"They always go on the field to win ... and they know we must beat Mexico if we want to go through to the knockout stage.