Nelsen said: "It is our catch-up game and a crucial one. If we can get some points there things will be even better.
"We've won away from home, we've ticked that box now so it has to be consistency for the next few games.
"We had 10 very difficult matches at the start of the season, possibly the hardest of any teams.
"Sure we were disappointed to only get 10 points from them but now we are looking at the next batch as really important ones.
"A year and a half ago we were seventh, so we've been really disappointed with what has happened.
"The past four or five years Blackburn have been easily a top 10 club and that is where we aim to be."
Assistant manager Neil McDonald will again take charge as Sam Allardyce is having an angioplasty, a procedure to widen one of his coronary arteries, on Friday.
Nelsen, like others, was caught on the hop by the news.
He said: "When the captain of the ship is having to step aside it is a big shock.
"But you've got to put your head down and be professional and get the job done.
"There was a little bit extra for him in this game against Bolton all the boys are really happy that we've given him the victory."
Fulham Evens, Draw 12/5, Blackburn 11/4