O'Driscoll has started every Ireland game since then and he won his 141st and final cap as Ireland clinched the RBS 6 Nations title in dramatic fashion in Paris last weekend but his retirement leaves a gaping hole in the Ireland back line.
Schmidt however, believes there are plenty of contenders for the No.13 jersey, listing Darren Cave and Robbie Henshaw - who have been involved with the training squads of late - Luke Fitzgerald and New Zealand born Jared Payne, who qualifies to play for Ireland in November.
"To be honest the search for his successors started when I got the job, and he and I sat down," said Schmidt.
"There were pretty clear parameters about how long he would be available.
"We've been doing that for the last nine months really, because we knew this day was coming.
"Robbie and Darren have been involved. Guys like Luke Fitzgerald who might play there a bit for Leinster.
"And Jared Payne would definitely be another guy in the frame. He's a class player, an experienced player and he has a natural intuition on the field."