Addicks boss Alan Pardew is keen on Pompey pair Martin Cranie and Marc Wilson and said: "Marc is a player I looked at and I feel has got a little bit more developing to do.
"I think he's a good player and someone I will keep my eye on, but I don't think he's someone Harry Redknapp wants to loan at the minute as he's a bit short himself.
"It's the same situation with Martin Cranie."
On Thomas' situation, Pardew also told Charlton's website: "There are some players here whose salaries are high and we will find it difficult to keep hold of them.
"Jerome could be in that category."