"We have to be [more focused]. I don't think we've played particularly well in a long time. I think we defended really well against Gloucester away from home and we played well against Leinster at home when we beat them at Thomond Park but I'd find it hard to put my hands on any big performances from us in recent months.
"You look at the squad that Toulouse have, the quality of player, the size of the men - it's an absolutely mammoth task we have. It's great to be at home and everything but this is an incredible team with incredible players and incredible talent so it's a massive task for us."
It will be the first time that Toulouse visit Thomond Park but O'Connell doesn't think the experienced French side will be fazed by the atmosphere at the famous Limerick venue.
"It's amazing that it's the first time they've come here but they've been to plenty hostile grounds in the past so I don't think it will be a big deal for them. I think it makes it a brilliant occasion for Munster and the supporters."
Munster captain Peter O'Mahony trained with the side yesterday after withdrawing from the side that were beaten at the weekend with a hamstring twinge.
And while O'Connell was playing in the 2008 Heineken Cup final when the sides last met, O'Mahony was in the stands as a supporter.
"I was at the 2008 final in the Millennium and that was obviously a good day out. I've followed Munster the whole way up so I've seen them a couple of times but in the flesh this time now!
"Toulouse coming to Thomond Park for the first time at half 1 on Saturday in the quarter-final of the Heineken Cup - it doesn't get much better than that. Whether you're a player or a fan it's going to be an unbelievable day out so I think everyone's looking forward to it.
"They've a huge back-row and they're very dynamic as well for such big men so we're preparing for their best team to come over.
"Regardless of who that is, it's going to be a quality side. We're going to have to certainly play the best game we've played all year to put ourselves in a position to win the game," said O'Mahony.
Along with O'Connell and O'Mahony, Conor Murray has first hand experience of playing against a number of this Toulouse side in the Six Nations last month.
"You just have to look at the amount of lads they had playing for the French team and how well they played in the Six Nations at times," said Murray.
"They have really threatening runners, especially their back three. They're a team that can be very dangerous, they'll run it from anywhere.
"They're a typically French team that will try a lot of things and sometimes they come off and look spectacular. So early on we have to be really aware of that sort of stuff and make sure we don't give them a soft opening into the game."