The striker scored four goals in his first five matches immediately after Sam Allardyce took over in mid-December but has not found the net since January 17.
He spurned a golden opportunity to win Wednesday's goalless draw at home to Everton - but despite glaring misses against Bolton, Middlesbrough and Sunderland, the Grenada forward is remaining upbeat.
"My goals per start is not too bad, I'll keep plugging away. To score goals, you have to miss chances," said Roberts, who has six goals in 15 Premier League starts.
"I'll keep my head up, keep positive and try to do the right things - and I know the goals will come.
"You have to keep being brave and getting in there. No striker in the world doesn't miss chances."
Roberts added in the Lancashire Telegraph: "Every game is critical now. We know what we need to do, and it's in our own hands.
"We have to believe in what we are doing. We still feel we're a good side and we'll be okay."
Prem Relegation 2008/09 Win Outright: Blackburn 9/2