This rumor comes by way of Football Italia, who are citing talkSPORT, so feel free to take this with as many grains of salt as you feel necessary. Martin Skrtel is apparently surplus to requirements at Liverpool, who are willing to let him go on a one-year loan. If he does leave, Napoli would be a likely destination, where he could re-join his former manager Rafa Bentiez, just like Pepe Reina did and Alvaro Arbeloa might do shortly.
Problem is, Liverpool aren't loaded at central defense. Kolo Toure joined this summer, but he's likely just a backup, replacing the recently retired Jamie Carragher. Andre Wisdom and Martin Kelly might be ready to take a step-up in competition, but if Liverpool's goal for the season is to capture fourth place in England, going into the season with players that inexperienced poised to play key roles is questionable.
There's also the matter of Skrtel's age. At 28 years old, his sale value isn't going to be high for very long. If Liverpool don't have Skrtel in their plans for the upcoming season, they'd probably be better off selling him than loaning him out. He wasn't spectacular last season, but was solid enough that he should be able to fetch a decent fee.
Don't make much of this for now, but this could become more of a possibility if Liverpool sign a central defender. Or if we hear about it from someone better than talkSPORT or Football Italia.