Pompey boss Steve Cotterill approached new Blues manager Andre Villas-Boas before Saturday's pre-season friendly between the two clubs.
However, Cotterill does not expect anything to be finalised for another fortnight as Chelsea are on tour in Asia.
"I had about a 20-minute chat with Andre (Villas-Boas) before the Chelsea game and mentioned to him we had already put in a request for a player before he got the job," Cotterill told The News. "I wanted to have that conversation face-to-face with him as opposed to just being a request going in.
"He has only just got through the door at the club and now has two weeks in Asia. Basically, he has two weeks away to assess his squad and, maybe, we will speak when we both get back.
"We are waiting to see what happens at the moment but nothing is set in stone. All I can say, though, is we have had conversations and, obviously, they are a fantastic club with a great squad there."