Fitzgerald was waived by the Panthers on Sunday, per Chris Johnston of TSN.
Fitzgerald agreed to a one-year, two-way contract with Florida on Monday.
Fitzgerald returned to being a healthy scratch in Saturday's 5-4 overtime loss to Winnipeg due to the return of Anthony Duclair (illness) to the lineup.
Fitzgerald will have to wait for his chance to play after being claimed off waivers from Buffalo by the Panthers, David Dwork of Local 10 Miami reports.
Fitzgerald was claimed off waivers by Florida from Buffalo on Wednesday, Elliotte Friedman of Sportsnet reports.
Fitzgerald was placed on waivers Tuesday, TSN's Chris Johnston reports.
Fitzgerald produced an assist, a plus-3 rating and two PIM in Monday's 8-3 win over the Red Wings.
Fitzgerald has played in two straight games for Buffalo after being scratched for the first three contests of the season.
Fitzgerald (lower body) will play in Friday's preseason finale versus Pittsburgh.
Fitzgerald sustained an undisclosed injury that kept him out of Monday's practice session, Mike Harrington of The Buffalo News reports.