It now appears that the changing of the guard has taken place in Jacksonville, with Leftwich taking the baton from veteran Mark Brunell.
The Dolphins defense is well aware of what Leftwich can do, but they're also cognizant of things they can do to take advantage of the fact they'll be going against a rookie making only his third NFL start.
"He's really not all that mobile," said safety Brock Marion. "He's a big guy. We'll give him different looks. He does look his receivers down. But yout can't take anything away from the guy. He's throwing the ball really well."
The Dolphins have seven interceptions in their last two games, and there figure to be more opportunities on Sunday if the Dolphins can confuse Leftwich by disguising their coverage.
Talking to the South Florida media on Wednesday, Leftwich expressed his admiration for the Miami defense, but he also isn't one to be afraid of a challenge.
The Jacksonville offense got a tremendous boost last week when five-time Pro Bowl wide receiver Jimmy Smith returned after a four-game NFL suspension.
He joins running back Fred Taylor to give Leftwich a couple of big-play guys on offense.
That's one of the reason the Dolphins aren't overlooking the Jaguars, who will come into the game with a disappointing 1-4 record. But that mark includes losses to Carolina and Houston on the last play of the game, as well as a loss to Indy where the Jags outplayed the Colts in the first half.
"On film they're a lot better than their record shows," said quarterback Jay Fiedler. "They played two undefeated teams, Carolina and Indianapolis, and they played them very tough."