Kaka moved to Real Madrid last summer, joining former United forward Cristiano Ronaldo at the Bernabeu.
United lost 3-0 in their last contest with the Rossoneri at the San Siro as Kaka inspired the hosts to a semi-final win in 2007 and Ferguson is happy not to be facing the Brazil playmaker.
“It’s a good time for us to be going to Milan,” said Ferguson
“They played this weekend (beating Udinese 3-2 on Friday night), they’ve lost Kaka and have a few injuries, whereas we have had a good rest.”
Tactically, Leonardo’s side have been forced to adapt since Kaka’s move to Spain, according to Ferguson.
He added: “They have changed since they lost Kaka. They used Kaka at the head of a diamond and two front players but they have changed that and gone 4-3-3 with two wide players and three centre-midfield players.
“You have to recognise they are not short of skill and experience.
“Ronaldinho, Pato all these players, but equally we have players who can win the match too.
“After the experience in the San Siro three years ago, where they dominated the game, I know that won’t happen again.”
Pato is outlined by Ferguson as the biggest threat to United in the first-leg contest, which may see David Beckham face his former club.
“It’s Pato they are desperate to get back in,” added Ferguson. “If he’s not back they’ll play David wide right.
“We know all about David, he’s a great crosser of the ball so we will have to be alive to that.”
Ferguson, whose side have won four of their last five games, scoring 16 goals, is confident United can cope in the absence of Ryan Giggs, who suffered a broken arm against Aston Villa last Wednesday.
“My players are used to big occasions and I think the good thing for us now is that we have hit form at just the right time,” said the United boss.
“We will miss Giggsy, but we have players in great form and working really well.’’
Meanwhile Ronaldo may play for Manchester United again one day, saying: “Maybe in the future I could return.”
The 25-year-old departed for Real Madrid in a world record £80 million (€94m) deal last summer after six seasons at Old Trafford, which yielded three Barclays Premier League titles, a Champions League crown and numerous other team and personal honours.
Ronaldo has made a strong start to his Real career, scoring 11 times in 13 Primera Division appearances – including two goals in Saturday night’s win over Xerez – and six times in four Champions League appearances.
But he may pull on a Red Devils shirt again. “Of course I miss playing for Manchester United,” Ronaldo said.
“I played there for six years and that’s a long time. I am still interested in watching United and, you never know, maybe in the future I could return to play there. It’s always possible.”