Earls has been handed the daunting prospect of replacing the talismanic Brian O'Driscoll, who will miss the entire tournament after undergoing shoulder surgery, in the No.13 shirt.
And the 24-year-old must step into some of biggest boots in world rugby only days after his partner Edel McGee gave birth to their baby girl, Ella-Maye.
But rather than be overawed by the demands of filling the void left by O'Driscoll's absence, O'Connell believes Earls will feed off the change to his home life.
"I've spoken to Keith and he's in good form," said O'Connell.
"I was lucky in that when we had our small fella I was injured at the time so I didn't have to go through what he's going through.
"It's a great time and he's in great form and is looking forward to joining up with the team.
"Having kids is great because it gives you a bit of perspective on life and rugby.
"We all take rugby very seriously and are a bit selfish at times, but it gives you perspective on how to treat games. Hopefully it will be a good thing for him.
"He's a lot more experience than in the past so hopefully I won't have to say a lot to him.
"He had a good World Cup and has been playing well for us. He was excellent against Northampton.
"Guys have to be trusted....we have to let him continue doing what he's picked for."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.