The 31-year-old swapped Italy for England last month after Chelsea agreed a loan deal with parent club Juventus , Milan letting the forward go after agreeing the transfer of Krzysztof Piatek from Genoa .
After failing to score in his first two Chelsea matches, Higuain looked sharp against Huddersfield Town as he scored a double in the 5-0 victory over the Terriers on Saturday .
"I still think he is the best striker in the world," said the defender, as quoted by Calciomercato .
"I am sorry he decided to leave but we respect his decision. He is a friend of mine and if he is happy I am ok with it.
"Now we have other players that won't make us regret his departure."
The other player he refers to is Piatek, the Polish forward having made a superb start to life in Milan with three goals in as many games in all competitions.
"We enjoy having him [Piatek] here and we hope he can keep scoring at least one goal per game," he added.
"We hope to win many more games so we can reach the Champions League.
"Piatek's impressed me with his desire and hunger. You can see he wants to show what he's all about and that's important. He's young and on the right path."
Higuain and Chelsea are back in action on Sunday as they make the trip to the Etihad Stadium to face leaders Manchester City.