"The Champions League is always something different but this year, more than ever, it is our season's main objective," Kaka told Milan channel.

Milan's Serie A title hopes this season faded after they were hit with a nine-point penalty following the match-fixing scandal that rocked Italy.

The Rossoneri were also knocked out of the Italian Cup at the hands of AS Roma and they are now looking for the last piece of silverware available.

The Brazilian sensation said he believes his team could outclass Celtic if they build on to their fine performance in the first-leg's goalless draw in Glasgow, while singling out Japanese midfielder Shunsuke Nakamura as the visitor's source of danger.

"We played a good game in Glasgow and we must give the same performance at the San Siro and score some goals.

"In the Celtic team, I particularly rate Nakamura, who is a very good and intelligent player.

"The main strength of the rest is set-pieces and aerial challenges. He [Nakamura] is good at priming them for both things," he added.