Preston are still at the bottom of the Championship following their draw on Saturday.
Ferguson said: “We might have to get results by grinding them out, especially where we are in the league.
“But on another day Iain Hume might have scored and then it’s a one-nil win.
“But we have got to build on the clean sheet and have to take positives out of the match.
“They didn’t threaten at all in the first half but second half we were a little bit susceptible to the counter attack and we had to chase the game and try and win it.
“At the end of the day we are bottom of the league and we have conceded way too many goals.
“Andy Lonergan got a little bit of criticism after last week and I’d like to think it gives him bit of confidence.
“His save in the first half – you won’t see much better than that.
“But we have got to build on this clean sheet. I’m not happy with the result – you have to win your home games.”
