Milan must sign Paris Saint-Germain striker Zlatan Ibrahimovic to end their four-year drought without a Serie A title, according to Antonio Cassano.
Ibrahimovic has been linked to Milan throughout the current transfer window, with club president Silvio Berlusconi claiming the Sweden international would be welcomed back to the San Siro "with open arms".
Cassano's two-year stint at the San Siro matched that of Ibrahimovic, and the former reckons Milan "cannot win the Scudetto" without the latter.
The attacking duo played together at Milan in the 2010-11 and 2011-12 seasons, combining for 49 Serie A goals and 39 assists.
Juventus have won the past four Italian championships, and when Cassano was asked which club would be best placed to challenge Massimiliano Allegri's side in 2015-16, the Sampdoria forward replied: "Together with Sampdoria, Inter are a team close to my heart. I hope Inter can win the Scudetto but it will be hard.
"Juventus are favourites for the next four or five years, with Roma able to cause them some problems.
"As for AC Milan, unless Zlatan Ibrahimovic returns they cannot win the Scudetto."
Since leaving Milan, Ibrahimovic has played three seasons with PSG, winning Ligue 1 each time and scoring 75 league goals in 91 appearances.
