Gray said: "Luke is a player who we have been impressed with when watching reserve-team football and who also impressed us in pre-season.
"He is a big, strong midfield player who will give us a presence in the middle of the park. I know there were some clubs in League One who wanted him so we are pleased to have got this loan sorted out.
"We are getting a reputation for doing things the right way and looking after young players well and I think that is why Luke chose to come here above the other options. We are delighted to have him as part of our squad and we are sure he can do well for us."