A brace from Rovers striker Jason Roberts either side of a Ruben Rochina striker saw the visitors record a comfortable victory after their hosts were reduced to 10 men after just 16 minutes.
"We have plenty of positives to take back with us for our game next week against Queens Park Rangers," Kean told the Lancashire Evening Telegraph.
"First of all, any game we play is worth winning. We were very respectful of our opponents.
"We are a little bit disappointed that they had a man sent off. The referee had to make the decision and obviously it was going to be a little difficult for the opposition.
"We had 49 shots on goal with almost 30 of them on target. It shows that our possession was good.
"We'll take that forward, it has been a very good week.
"It was a great week for the guys to spend a lot of time together. We can go back with our heads held high.
"We would love to come back, either at the start of the season or during an international break."