The Dolphins signed Sage Rosenfels to replace Henne on their roster, but heading into the bye week, Sparano is more comfortable with Moore, whom the team signed during the offseason.
"It's Matt's job," Sparano said. "We got to get Matt ready to go."
"I don't think there's a team around that wants to lose their starting quarterback," the coach said. "To catch those people up with reps is hard to do."
"It's really disappointing," Sparano said. "The kids obviously had a lot invested in this whole thing."
Henne separated his left shoulder while tackled on a busted play during the first quarter of last Sunday's loss at San Diego. The game might have been Henne's last with Miami, because his contract expires after the season.
Henne, a second-round draft pick in 2008, lost his past seven starts for the Dolphins. He's 13-18 overall as a starter in Miami and has thrown 31 touchdown passes and 37 interceptions in 36 total games.
Moore took over against the Chargers and will make his first start for the 0-4 Dolphins in their next game, Oct. 17 against the New York Jets. Moore took 150 snaps during three days of practice this week, when the Dolphins' only other healthy quarterback was rookie Pat Devlin, a member of the practice squad.
The Associated Press contributed to this report.