Marcelo Bosch misses the quarterfinal after being sin-binned against Namibia © Matt Lewis - World Rugby/World Rugby via Getty Images

VALE OF GLAMORGAN -- Marcelo Bosch has become a key part of the Pumas team since the 2011 Rugby World Cup in New Zealand. He played all the Rugby Championship matches at outside centre, first with Santiago Phelan and later with Daniel Hourcade. but he'll miss Argentina's biggest match of the year, against Ireland in the quarterfinals, after his dangerous tackle in the match against Namibia, minutes after going onto the pitch, and Juan Martin Hernandez acknowledges that Argentina will miss his defensive leadership.

"He's a great leader for the backs on defence," Hernandez said. "He's the best at reading situations. Both for the outside centre and the wing, tackling is very unpredictable and you have to make good decisions. He always does well."

Hourcade favours a more offensive approach, and he has tried different options with Matias Moroni, and even briefly with Horacio Agulla, but Bosh has always started the toughest matches. He played 15 matches out of 23 under Hourcade, and he started as at N0.13 against the All Blacks in their Rugby World Cup opener at Wembley. The idea was to have him start in the quarterfinals after resting him against Tonga and playing from the bench against Namibia.

"As a player, we lose a lot," said Joaquin Tuculet, who also earned a starting role with Hourcade. "He really has established himself over these last few years in the centre partnership. But we are also sorry for him as a colleague and a friend. It hurts that he has to live it from the outside."

Bosch is not only a defensive leader, he also provides an option as a kicker - particularly his long distance penalty-kicks, which the All-Blacks suffered in 2011 and the Springboks this year in Durban - and offers a tactical game.

Moroni has finally been chosen as Bosch's replacement, ahead of Jeronimo de la Fuente, Horacio Agulla and Santiago Gonzalez Iglesias, but none of the possible replacements had what 'Chelo' offers. "It will be very important for whoever comes in to make good decisions on defence; maybe not with the experience he has, but doing the best they can," Hernandez said.

The Puma hope the World Cup is not finished for Bosch, and that means winning at Millennium Stadium in Cardiff on Sunday. "We are already thinking about the match and we want to reach the semifinals so he can come back," said Tuculet. "We told him that we will do everything we can to make it."