Sexton picked up a calf injury in Leinster's 24-24 draw with Castres on Friday, and Schmidt said even if he does not pull through, Paddy Jackson is an able deputy, with uncapped centre Rory Scannell also an option at number 10.
"We are pretty confident that there's not a lot of damage there. Johnny is starting back doing a little bit, we'd be confident he'll be able to train next week and therefore be fully available for Scotland," Schmidt said at the tournament launch in London on Wednesday.
Schmidt also hinted at a possible recall for flyhalf Ian Madigan, who plays for Bordeaux Begles in France, although said Irish-based players tend to be favoured over those plying their trade abroad.
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"He would slot back in seamlessly for us and that is potentially something we could look at," Schmidt said.
Alongside holders England, Ireland are favourites for the 2017 tournament after wins over New Zealand and Australia last autumn.
Schmidt said he was aiming for a "top two" finish but added that it was the most competitive tournament he had faced in four years as Ireland's coach.
Ireland play Scotland at Murrayfield on Feb. 4.
(Editing by Angus MacSwan)
