The 22-year-old is a product of the United youth system, but only ever managed one Premier League appearance in his time with the historic club.
Loan spells elsewhere have included stints at Leicester, Derby and Blackburn, while Keane spent the first half of 2014-15 on a temporary deal at Turf Moor.
Having featured in ten league games this term for Sean Dyche’s men before his permanent switch, Keane believes that he has made the right decision to leave United.
“It was a big decision,” Keane revealed to BT Sport.
“I spoke to my family about it for ages because I had been there for nearly 12 years now. But I felt it was the right time, especially as I am playing regularly and I wouldn't get that at United at the minute.
"They didn't force me out, but they said if everyone is fit there I wouldn't be starting games. I thought I am playing games here and at my age I have a chance to play regularly in the Premier League and that's all I ever wanted, so it was quite an easy decision in the end.
"Now we want to stay in this league and we believe with the performances we have been putting in recently we can do.”
Keane played the full 90 minutes in Burnley’s essential 2-1 win over QPR at the weekend.
Given that youngsters Tyler Blackett and Paddy McNair have been brought into Louis van Gaal’s first-team selection process at Old Trafford this season, the 22-year-old may feel aggrieved at not having more chance to play for United in the past.