The Leicester forward spent much of last season on loan at Deepdale but returned to Leicester at the end of the season. His parent club had just gained promotion and it was unlikely that Gallagher would be breakinbg into the Leicester first team.
The two clubs have simply been spending the last few weeks negotiating over the percentage that Preston will contribute towards his wages on a year long loan deal. There is no recall clause int he loan so at the end of teh deal Gallagher will become a free agent as his contract with Leicester formally expires.