I think he only got back from South America on Friday, or something like that - he looked knackered after 65 minutes, so Hughes took him off. The right decision in my book.
It wasn't his most effective game, but the fact that he drew Blackburn players away to the left to mark him, leaving Ade with space to score the first was a big part in that goal - which gave us the platform to win the game. He also had 2 shots on goal well saved by Robinson. That's a pretty good contribution for a player not having his most effective game I'd say.
As previous posters have pointed out - players like Robbie struggle a bit against long-ball merchants like Blackburn are now. He'll have plently of better games this season, and remains one of our most important players.