The 20-year-old made 15 appearances for Dale during a loan spell from Rovers earlier this season, forcing summer signing Lucas onto the bench, before being recalled after an injury crisis at Ewood Park.
The England Under-20 international is still waiting for his first-team debut for Rovers, but Lucas believes that Kean has all the attributes to become a top keeper.
"It wasn't something that I was unaware of because when I wanted to move back up north in the summer and the gaffer said that he'd like to bring me here, but that he'd already done a deal to bring in Jake Kean from Blackburn, so I knew that I wouldn't start as number one," Lucas told skysports.com.
"Jake did very well and it was just a chance to use my experience a little bit to bring the younger lads through when I wasn't in the side.
"It was up to whoever was in possession of the gloves to keep hold of them and obviously that's me now and I intend to do so for as long as I can because we've still got some good young keepers here pushing me all the way.
"He (Kean) is pretty much what you expect from a Premier League club because technically he is very good, with all the attributes that go with it, but as with any youngster he just needs game time and confidence.
"I'm a big believer that a keeper has to become somebody else when they are on the pitch and I don't think he has mastered that yet.
"Once he realises that he has to come out of his shell a little bit and be a bit more aggressive he can be a world beater."