The Reds dominated throughout a one-sided clash at Anfield, but needed a late Steven Gerrard penalty to salvage a point after goals from Christian Benitez and Cameron Jerome had cancelled out David Ngog's opener.
"We are asking ourselves why we aren't winning matches, but sometimes you don't have the answer," Lucas told Liverpoolfc.tv. "We created lots of chances; we had all the possession and did almost everything you need to win a football match.
"We played with intensity and quality throughout the 90 minutes. We tried our best but the third goal just wouldn't go in.
"All we can do is train hard, keep going and try and change the situation as soon as possible.
"We must stay positive. Maybe the international break will be good for us. We will get some players back from injury and hopefully everyone will be fit to play against Manchester City."