Ireland coach Eddie O'Sullivan insists his policy on substitutes remains unchanged despite drawing heavy criticism for his stance.

O'Sullivan is reluctant to use the bench, claiming it takes too long for a replacement to adjust to the intensity and pace of a Test match.

Other nations include impact players among their substitutes with giant winger Lesley Vainikolo fulfilling such a role for England against Wales on Saturday.

In the past Argentina have named an entire front row on the bench with a view to pulverising opposition scrums late in the match.

O'Sullivan was blasted for failing to use replacements during the World Cup but the 49-year-old insists it will be business as usual for tomorrow's Six Nations opener against Italy.

"Substitutions are my decisions. We make substitutions late in the game occasionally - if we're in a certain position," he said. "We don't tend to make substitutions in blocks. I'm not going to change my philosophy on substitutions. I've done the same thing for however many years now.

"I have a logic and a reason why I do it. I know people don't agree with that, but that's okay."