The 25-year-old is desperate for first-team football after fighting back from injury problems.
Gray said to the Yorkshire Post: "I have spoken to Michael and we will review the situation before the end of the month and see what's happening here.
"I understand how he feels, he wants to be playing matches at a higher level, and if he is not getting games here he wants to get them elsewhere.
"But he needs to be patient and he could find himself back in action sooner than he anticipates, I have told him that.
"Michael's been out a long time and it is not always a physical thing, he needs to realise that he is 100 per cent fit," added Gray.
"His injuries have been a big blow to the club when you consider how he performed in his first season."
Bridges come on as a sub in tonight's game against Newcastle for Seth Johnson in the 69th minute.