But Johnson is prepared to let the former Ebbsfleet man stay at Adams Park until the end of the campaign with first-team opportunities unlikely to arise at Ashton Gate.
"It looks as though John will be staying out on loan until the end of the season," Johnson told the Bristol Evening Post.
"He's still only a kid and he's learning the game. For John, it's all about playing games and getting experience at this stage of his career, and he's getting both at Wycombe.
"We've watched every game he's player for them and he's done very well. We're speaking to Wycombe and they are keen to keep him. There are other, more experienced strikers, ahead of John in the pecking order here and it makes sense for him to be getting regular games at a good level in a team which is doing well."