"We are in the final stages of dealing with all the necessary paperwork."
Trollope had been keen to re-sign Reading keeper Mikkel Andersen, who spent last season on loan at Rovers, but has now turned elsewhere.
"It may take a few days before we can make an announcement but we are confident that the agreement is in place and a new keeper will be joining us," Trollope added.
Trollope has already made four summer signings and stressed that he is still looking for more recruits.
"It doesn't mean we have stopped looking for other players to add to the squad," he said.
"We have moved through our list of priorities.
"We still need a central defender to add to competition for places and we also need a big striker.
"Now we will turn our attention to filling those positions."
Rovers' first pre-season friendly is away to Bath City on 14 July.
Source: BBC Sport
