Keane could make his debut in Sunday's Lancashire derby against Burnley.
"I've got a bit of experience now in the Championship and I know what it takes to play well in these games," the 21-year-old told the club website.
"I'm looking to play well on Sunday and hit the ground running and keep that form up.
"I'm sure it will be a tough game but I'm confident we can get a result.
"I'm really looking forward to it. I hope it's my debut and I'll make sure I'm ready to do well."
"He is highly sought-after," said Rovers boss Gary Bowyer.
"He has had a good education with Manchester United and he has got experience already in the Championship with his time on loan at two top clubs."
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