AC Milan boss Pippo Inzaghi admits they need to improve at the back after their 2-0 defeat to Palermo.
An own goal from Cristian Zapata and Paulo Dybala's strike earned Palermo their 2-0 win.
The Diavolo have kept only one clean sheet all season, although this was the first time they've let two in at home.
Inzaghi said: "We have players who can almost always find a goal, so the defensive movements are more important for me. When you suffer at the back, it means the whole team hasn't worked well.
"Then Alex went off straight away, Zapata had to go on without a warm-up and he immediately felt some pain too. It was just one of those nights.
"I am the Coach, I'll try to work out where I went wrong, but this squad must be allowed to grow in good time. It was a heavy blow, but we'll get back up.
"I tried to change system and introduce almost all the strikers at my disposal. Perhaps the third game in seven days took its toll on our fitness levels. We must remember the team has done well until now and this was a stumble, but we'd be right back up there if we beat Sampdoria next week."
