Smith threw three interceptions and conceded a safety in the Jets' last pre-season match against the New York Giants as he continues to battle Mark Sanchez for the starting quarterback jersey.
Ryan has so far refused to confirm who his first choice will be, but an injury to Sanchez could force his hand, and the Jets coach insists that he would be confident with Smith starting.
"I think Geno's done a lot of really good things," Ryan told reporters.
"Did he have a rough night [Saturday]? Yes, he absolutely did. But again, I feel confident in him."
The Jets will begin their regular season against the Tampa Bay Buccaneers on September 8.