He saw his side creep past Crewe to stay top of League 1.
City boss Pearson said: "This was not one of our better performances and I think it was disappointing, not just for me but for those who watched it.
"We did so well away from home on Saturday, but really this time we made hard work for ourselves. The two wins were very different.
"I don't think it was convincing and some of the things we did were uncharacteristic. It all added up to a frustrating evening.
"But we got the three points and that is the most important thing. It is about playing winning football - and we would like to play attractive football although it has not happened in every game."
Pearson added: "We are sitting top of the league, but I think there is still a lot of room for improvement."
The Foxes have a break this weekend from League action with all attention on the FA Cup. Leicester host Dagenham & Redbridge with the winners getting a place in the hat for round 3.