The former Atletico Madrid midfielder has struggled to hold down a place in the Serie A side's team since his summer move.
The Hornets had been in advanced negotiations with the Serie A club about a move for the 28-year-old up until last week, Sky Sports claims. However, those discussions failed to reach an agreement, and thus, the move appeared to be off the cards.
Now however, the Premier League side are back in the running to sign the former Atletico Madrid man, with Sky Sports reporting that the proposed deal will see Suarez move to Vicarage Road on loan, but will include a clause that could see the move made permanent in the summer.
The Spain international may well be relishing the prospect of joining Quique Sanchez Flores' side during this window as he has struggled to make an impact with the Italian club since joining in the summer, having only started five league games for Fiorentina.
However, he arguably still faces a challenge if he wishes to hold down a place in Watford's team. Etienne Capoue and Ben Watson have been excellent in the middle of the park this season, and the manager may be concerned about rocking the boat too much.