Shearer has been linked with the manager job at Ewood Park, following the sacking of Paul Ince on Tuesday.
“They need to spend in the transfer window because the squad has clearly not got the strength it needs,” the former England captain said in The Sun.
“If they go down they could find it very difficult to come back up because it is getting much harder for clubs to bounce back.
“I think Blackburn see themselves as a top-10 club and so they should.
“Well if they want to be that they are clearly going to have to spend.”
