MM is set to enter contract talks with forward Derek Riordan, whose short-term deal runs out at Christmas.
But the Rovers boss says fellow Scotsman Riordan, who has failed to score in 12 appearances, is going to have to impress in order to stay at the Memorial Stadium.
"Derek not only has to do a bit more but he has to convince me about his desire to be here," said McGhee.
"It's been difficult for him - his wife had a baby and had all his legal stuff going on. We have to know how he feels about all of that before we can offer him anything."
But the Rovers boss says fellow Scotsman Riordan, who has failed to score in 12 appearances, is going to have to impress in order to stay at the Memorial Stadium.
"Derek not only has to do a bit more but he has to convince me about his desire to be here," said McGhee.
"It's been difficult for him - his wife had a baby and had all his legal stuff going on. We have to know how he feels about all of that before we can offer him anything."
