AC Milan's Brazilian superstar Kaka has vowed to punish Celtic's "weak points" and keep his side on target for Champions League glory.

The midfielder is full of confidence ahead of tomorrow's Champions League showdown in the San Siro and insists they will reach the quarter-finals by exploiting deficiencies in Gordon Strachan's squad.

Kaka acknowledges that Scotland's champions will be a threat after a goalless first leg, though, and identified Shunsuke Nakamura as the man capable of ending their trophy ambitions.

"We played a good game in Glasgow and we must give the same performance at the San Siro, and add some goals," he said. "We must take advantage of their weak points.

"I admire Nakamura; he is a very good and intelligent player. As for the rest, their strong points are set-pieces and headers. He Nakamura is good at delivering both of these things."

With Milan out of contention for the Serie A title, the Champions League remains their best chance of winning a trophy. "Today more than ever, our primary objective of the season is the Champions League," said Kaka. "We all feel we must really prepare well for this game."

Kaka has pleaded with home supporters to get behind them tomorrow. The Milan fans sat in silence early in their side's 3-1 Serie A win over Chievo on Saturday and Kaka insists their backing will be required against Celtic.

"I don't know why the fans didn't chant against Chievo, but it is really strange playing without their chorus in the background. I am happy that, at the end, they chanted and said that they support us. Perhaps they don't know this, but fans are really important to us."

The Austrian referee Konrad Plautz will take charge of the Milan-Celtic tie. He officiated in Celtic's UEFA Cup home tie against Teplice which Martin O'Neill's men won 3-0 three years ago.