At that stage any chance of a third Lions tour looked unlikely, but the 33-year-old lock worked hard on his rehab and fitness, while his team mates battled to keep Munster in the running in the Heineken Cup.
The two efforts combined to give O'Connell a chance to fit in a Heineken Cup quarter-fiual and semi-final on his return to not only convince the Lions selectors he was still up to scratch, but also give himself the chance to return to big match fitness.
Now he is back to near the peak of his powers in time to try to make it two Test wins in a row for the Lions following the victory over the Springboks in Johannesburg four years ago.
"I was lucky to get back as early as I did from the operation. All along it was a case of it wasn't so bad that I needed an operation, that we thought it would come right," said O'Connell.
"So. then when I did need it, I wasn't as bad as some people are when they need to get their back operated on. I was lucky to get back, I was lucky the Munster lads had hung in there and managed to stay in with a shout for the Heineken Cup so I got to play in those two big games against Harlequins and against Clermont.
"I also had a big RaboDirect PRO12 game against Leinster as well, which was probably the toughest of all the games I played. It was good to get back and play in those games and I'm delighted now to play in the Test team.
"Even during the summer, when I didn't make the tour with Ireland, at the back of my mind I was half thinking that it wasn't the end of the world with the Lions tour the next year. I was thinking I could get a good pre-season and be in pretty good shape.
"Then I didn't even get a pre-season. I did know that if I did get back early enough I was in with a shout and, luckily enough, the lads produced that big performance against Racing Metro.
"I found a bit of form early, managed to get a few games with the A side and with Young Munster and now I'm in bonus territory."
You have to go back to another great Lions lock, Martin Johnson, the man who led the Lions on the 1997 and 2001, for the last player to play in seven successive Tests for the Lions - Johnson actually did eight in a row from the 2nd Test in New Zealand in 1993 to the 3rd Test in Australia in 2001.
On Saturday, O'Connell will be one of an unprecedented three Lions captains in the touring team's line-up as he joins the 2005 skipper Brian O'Driscoll and current leader Sam Warburton. Too many cooks?
"Certainly, it's a massive game and there'll be a lot of emotion attached to it on Saturday. I'm sure I'll have plenty to say, and I'm sure Brian will as well as a few other guys," admitted O'Connell.
"But the way we've built for games up to this point has been very good and we wouldn't be trying to change a whole lot. We'll be trying to make sure we continue the way we have been and make sure guys produce the best they can individually across the pitch.
"A lot of guys have shown some really good form on the tour and we need to continue that. We need to be a tight team as well, that's massive, but individually we need to produce big performances.
"Everyone's mind-set is that they want to win - we want to play rugby and we want to win, and that's the way we've been since day one. From a Lions point of view we certainly need to produce something and win a series.
"The pressure is on to do that. There is always pressure in big games; it's no different than what it normally is for a big game with your country or a big Heineken Cup game with your province - pressure is pressure.
"We're well aware that we need to produce something and produce some big performances at the weekend, and try to get the series off to a winning start."