"Shane and Amaretto d'Arco are experienced at a high level and have put in some good performances in Super League Nations' Cups for Ireland," said showjumping manager Robert Splaine.
"Significantly, Shane produced a solid performance as anchor man for the team at Calgary last week where the team finished second. Also the combination are particularly familiar with the arena in Kentucky as they base themselves there for part of the year," he said.
Robert Splaine also confirmed that Jessica Kurten and Castle Forbes Cosma were available as a European-based reserve but will travel only if anything happens to any of the European-based combinations before they fly to Kentucky.
"I had selected Jessica with Castle Forbes Cosma for the Super League Nations' Cup in Rotterdam earlier in the year but Cosma picked up an injury in the Global Champions' Tour in Cannes in June and was unable to line out for the team in Rotterdam.
"However, she is now back in action and I believe at this stage she is the best remaining European-based option especially since Shane Breen's horse Carmena Z hasn't recovered sufficiently from a virus," he said.
"I want to make sure we travel four horses from Europe to give me the best possible choice when we are at the games," he added.
Jessica's top horse Castle Forbes Libertina was an obvious choice for the squad but unfortunately is unavailable for the games due to an injury picked up at Global Champions' Tour in Estoril in July and will not be back competing in time to be ready.
Robert Splaine said that Darragh Kenny would be on standby in the USA if needed.
"Darragh did well in Nations' Cups earlier in the year and I was looking forward to seeing how he and Obelix went last Sunday in the Grand Prix at Saugerties, New York, but unfortunately he didn't compete," he said.
"All in all I believe we have covered as many eventualities as possible, we have our victorious Aachen team in place, there is an excellent atmosphere in the camp and we have a good chance of achieving our main goal of Olympic qualification," he said.