Kean believes that the young forwards will become an integral part of his plans during the 2011-12 campaign - and for many years to come.
"They were ready, but it probably just wasn't the best time to put them in," the Rovers boss told the club's website.
"If we'd have got another couple of victories and were a couple of places higher, then it would have been worth putting them in.
"Certainly from Mauro's point of view, I felt it was the wrong time to put him in.
"Ruben got a couple of cameo appearances as sub and was then unfortunate to dislocate his shoulder, as he probably would have been involved in the Manchester United and Wolves games, so that was disappointing for him.
"People have seen what kind of skill and what kind of ability that lad has got, whilst Mauro is different, but he's got other qualities.
"Both of them are fantastic talents and I think they'll go on to do really, really well here."