Lucas replaced Fiedler near the goal line in the Hall of Fame game against St. Louis and scored on a quarterback sneak.
Lucas also was used against Tampa after Fiedler had put the Dolphins in a second-and-goal from the 3-yard line. Lucas was stopped after a 1-yard gain on second down and Autry Denson was stopped after another 1-yard gain on third down.
The Dolphins then decided to settle for a field goal, but Olindo Mare missed a chip-shot 19-yard attempt.
The Dolphins also experimented with wide receiver Bert Emanuel — a former college quarterback — in short-yardage situations last preseason.
But after using Emanuel at quarterback in the season opener against Seattle and being flagged, the Dolphins dropped the idea — even after the NFL altered its rules pertaining to quarterbacks having to wear a certain number.
How often the Dolphins wind up replacing Fiedler with Lucas in short-yardage and goal-line situations this season remains to be seen.
"I know Jay, and he wants to win," Wannstedt said. "Whatever we've got to do to score touchdowns. ... More times than not down there, we're going to be running it anyway.
"For the difficulty and the problems it presents the defense when you bring someone like Ray in and you've got four or five different things you can do — and do effectively — I think that's a plus for the team. The other thing is that it's not going to be a locked-in thing every week. If it fits that week and there's some rhyme and reason to doing it, we'll do it."