The Danish winger is out of contract after his short-term deal with Newcastle expired this summer and has returned to Glasgow to maintain his fitness.
Rangers claim they are "helping him get fit", but played down any return.
He made 182 appearances for Rangers between 2000 and 2006, but it is unlikely he will make a permanent return to the Scottish giants.
Agent, Ivan Marko Benes: "I really don't wish to comment on that.
"He is training with Glasgow Rangers - not with the team but by himself. He is using their facilities.
"I believe that we will find something for him before the transfer window shuts.
"Peter is positive, and it is still England that is his first priority."