The veteran forward has battled calf injuries for the last three seasons and sustained another strain to his left leg ahead of the Super Rugby match against the Bulls in Pretoria last week.
He was a late withdrawal from that game and Blues coach John Kirwan said Mealamu, who turns 35 next week, had not recovered sufficiently for their clash with the Lions in Johannesburg on Saturday.
"It's a real blow for us," Kirwan said in a statement. "He just got a little strain in his calf and when you're a front rower that's like a sprinter having a hamstring problem.
"So we're just erring on the side of caution because we want to make sure Kevvie is with us for most of the season.
"We've decided to protect him a wee bit, send him home and not take the risk because if he blows it he'll be out for 12 or so weeks."
Mealamu said the strain was at the lower end of the injury scale and hoped to be fit to play South Africa's Cheetahs at Eden Park on March 22.
"I'm ... really gutted that I'm not able to stay on with the team," Mealamu said.
"It's just one of those things, I really want to help the team out but I can't do that unless I'm one hundred per cent.
"I'm hoping to be back for the Cheetahs game so I'm close to being back out there, I just want to make sure its right."
Mealamu's continuing battle with his lower legs will be of concern to Hansen, who will be hoping to have a good idea of his squad for the 2015 World Cup in England by the end of this season.
Fellow veteran Andrew Hore retired from professional rugby after the end-of-year tour to Europe, requiring Hansen to blood a new test hooker in 2014.
Wellington's Dane Coles has been anointed as the likely successor to Hore but none of the other Super Rugby level hookers have looked up to international standard yet
That has left Hansen reliant on Mealamu being able to make it through to the global showpiece in late 2015.
The All Blacks host England in a three-test series in June, with Stuart Lancaster's young side looming as a threat to the world champions' title defence in 18 months time.
(Reporting by Greg Stutchbury; Editing by Nick Mulvenney)
