The skipper believes Rovers have come a long way this season - manager Mark Hughes' first full term in charge - and his team have steered a course into fifth place in the Premiership standings, three points behind ourselves going into the weekend fixtures.
"They have and have progressed well under Mark Hughes this year," considered Ledley. "They have got good players and are another team who are not easy to play against, they work hard, make life difficult for you and we are expecting another tough game at home.
"It is one that is winnable for us and we'll have to play better than against Wigan, that is for sure."
The England international, who featured in the second half of the win over Uruguay on Wednesday, knows slip-ups cannot be afforded with Rovers now within striking distance following their win over Arsenal last time out.
"Of course, there are plenty of points left to play for and, while they are there, quite a few teams are involved in it. If they put a good run together they will stand as good a chance as anyone.
"No games are easy, although sometimes they might look easy if the team does well. Blackburn have got some good attacking forwards and, if we are not on our game, it is one we could lose.
"We will have to be right for it."
Ledley King believes Blackburn Rovers present a significant threat to our ambitions of three points at the Lane on Sunday.