Former Magpies Sylvain Distin and Titus Bramble, as well as current St James's Park favourite Sebastien Bassong, are just a few names on the radar.
Distin looks to be on his way out of Fratton Park, and Liverpool are understood to have put in a £2m bid for the Frenchman.
Distin: "Right now I expect to be here next season. I'm not in touch with anyone, but you know how it is in football. A lot of things can happen in the coming months. We don't know what is going to happen."
The 31-year-old will be out of contract in 12 months time and Pompey may decide to sell him now rather than risk losing him next summer for nothing.