The Foxes have picked up just one point from the last 18 on offer in the Premier League and are yet to even score in the top flight since the turn of the year.
That form has left the champions in 17th place, just one point clear of the relegation zone, and Ranieri admitted that he is struggling to identify exactly what the problem is.
"It's difficult to say what's right or wrong. For me it's important to stay close together with my players. We fought last season, fought this season, and will continue to fight. The mood will change," he told reporters.
"Of course we have to improve a little everywhere - just one per cent in every area and then that becomes a lot of per cents."
"[Slimani] feels something in his groin and we are waiting for him. For this match he is not available," he added.
"[Ulloa] has started to train but not properly because he always feels something. Today he didn't finish the session and then we have to wait to see him back. I can't tell you something until the medical staff tell me he's 100% fit."
Despite their domestic struggles this season, Leicester will return to Champions League action for the knockout stages next week.