Rovers added Grzegorz Sandomierski, Nuno Henrique and Diogo Rosado to their squad on Friday after they were recommended by global adviser Shebby Singh.
Kean told BBC Radio Lancashire: "I've not seen them play live. They're in the club now and we can have a real look at them.
"These players have been identified by Shebby and he's been very excited about the technical abilities of these players. You can't have too many good players.
"We feel as though we can improve any player that comes to the club and also integrate them as quickly as possible.
"If they show the signs that they can compete straight away, they'll get thrown in."
- Diogo Rosado