The Rossoneri currently sit one point above the Bianconeri in the standings, but Antonio Conte's men have one game in hand.
Ambrosini is unwilling to attach too much importance to the pair's eagerly-awaited meeting at San Siro but the veteran midfielder concedes that it will have a massive bearing on where the Scudetto ends up this season.
"It's an important game in terms of the table, but I don't think it will be decisive in terms of the title because there are many games left to play," the Rossoneri skipper told Milan Channel.
"Of course, the team that wins will have a psychological advantage but we must face Juventus head-on because teams like Juve must be confronted without fear."
Milan are still on a high at the moment after last week's 4-0 Champions League victory over Arsenal but Ambrosini feels that the club's exploits in Europe will ultimately prove a hindrance when it comes to trying to hold onto their league crown.
"I think the fact that Juve have no European commitments is an advantage for them," he claimed.
"They play only on a weekly basis and that allows them to be in great condition for every game."
Milan's meeting with Juventus at the Giuseppe Meazza kicks off at 20.45CET.
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