The City boss has seen his side slip from second place in January to sixth spot going into Friday night's home game with Millwall.
Leicester are clinging on to the final play-off berth on goal difference after five defeats in their last nine Championship matches, a sequence that has returned only one victory.
Pearson insists his team must snap that run as soon as possible or risk seeing their season fizzle out.
He said: "There has been a lot of hard work to get into a decent situation, but there is no doubt we are putting our opportunity in jeopardy with this poor run of form. We can't hide from that.
"Although our form is poor, we can salvage the situation. But we have to rectify this quickly. It is effectively an eight-game season now and we have got to make some serious inroads.
"First things first, Friday's game is pivotal. We want to get back to winning ways and that means putting in a good performance on Friday.
"We want to make sure that we can finish the season strongly. What that means in terms of where we can finish, of course the minimum has to be the play-offs.
"I am not prepared to let this opportunity pass us by because we have hit a poor run of form."