Sportal.co.nz 07.Feb.2014Getty Images
O'Connell's side managed without their on-field leader, winning 28-6 in Dublin, but ahead of hosting two-time defending champions Wales on Saturday, Ireland's skipper revealed his shame at being forced out at the 11th hour by a virus.
"I've just got a little bit of a cough left, that's all," the second-rower said, after being named in the starting XV for the Wales clash.
"It's a bit embarrassing really; I've copped plenty of slagging from the old-school players I've played with for years.
"I've just finished a course of antibiotics. I've played matches on them before, so I don't struggle with it at all."
Ireland coach Joe Schmidt said he could do without the late drama this weekend, with the might of the reigning Six Nations champions before them.
"If we get through Saturday morning with him he'll be fit and ready to go," Schmidt said.
"He trained fully on Thursday and I'm confident there will be no late changes this time around.
"As soon as I saw the name on my phone on Sunday I knew something was up.
"The doctor doesn't ring at eight in the morning to ask if I want to go for a coffee."
Along with O'Connell's return to the starting XV, Gordon D'Arcy returns in place of Luke Marshall at centre, with the skipper coming in for Dan Tuohy, who played in the number five shirt against the Scots.
D'Arcy will partner Brian O'Driscoll in the centres, with the spotlight on the latter as he takes on a side coached by his British and Irish Lions mentor Warren Gatland.
O'Driscoll was dropped by Gatland for the third Test of the Lions' tour of Australia last year, and later revealed he resented the coach for replacing him with Jonathan Davies, who has just returned to Wales' squad for this weekend's clash.
But Wales assistant coach Rob Howley said his players will not be affected by the sidebar.
"The experiences the players have had with Wales and the Lions in big matches means they can deal with intensity and hype and the media," he said.
"Experienced players become automated, having been there and done it.
"Gats [Gatland] has been no different this week to any other; experienced and astute, talking to players he feels he needs to speak to and making sure our environment is ready for the players to be the best they can be on Saturday afternoon."