The much-travelled 34-year-old has swapped sweat with many an Argentinian in his remarkable 14-year career and has a deep respect for their passion for the game.
“They can be temperamental and emotional, and always very competitive. It is why they are so physical. I played with and against enough Argentinians overseas to know what makes them tick,” said Claassens, who could not be more opposite in personality to the Argentinians he is describing.
Modest, humble and a touch diffident, it takes a lot to raise the ire of the Kroonstad-born Claassens. In quietly getting on with the game, he has amassed a total of 324 first class games, 164 of them for Bath and 37 for Toulon, the balance being for the Cheetahs, Cats and the Sharks, not to mention eight Tests for South Africa.
A good number of the Jaguares players will be revisiting the Stadium that witnessed one of the greatest moments in the history of Argentinian rugby - their first win over the Springboks (in 2015), and that will no doubt get the blood boiling.
“Last year the Jaguares probably overdid it with their physicality in what was their first season of Super Rugby, and they have learned from that (they had an endless run of yellow and red cards),” Claassens said.
“This year they have a shrewder approach to their game, and it is working for them,” he said. “They are not as reckless as last year when they ran the ball from any situation. They have added a tactical approach for when they are in their 22. They have very good kickers to get them out of danger.”
That said, Claassens says the ardour of the Argentinians has not been dampened.
“They have not lost their aggression. They are just being more controlled. We must not forget that they were a new team last year, even if most of them had at some stage played for the Pumas, and it takes a season or two for a team to gel,” Claassens said. “We are seeing that. They are a different team now that they know what Super Rugby is all about and have had a season of playing together.”
Even though the Jaguares are trying to keep a lid on their fiery temperament, they remain probably the most robust team in the competition.
“Discipline is a major focus for us this week. It is everything,” Claassens said. “Our discipline has been very good this season. Although last week against the Lions we gave away more penalties than usual
“On Saturday we must not get involved in scraps off the ball. If we want those vital log points, we have to keep our cool,” he said.
Next week the Sharks have a bye and their holiday will be that much sweeter if they bank this win.
“We want this one. The guys were very positive in the changeroom after the Lions game. The talk was soon about fixing it and getting these crucial points,” Claassens said.
The Sharks seem to be a team enjoying their rugby and the experienced Claassens reckons he is qualified to recognise when a team are on the right track. “I am convinced this team will be very successful possibly this year and certainly next year.”