Milan head coach Stefano Pioli said the signing of Zlatan Ibrahimovic has been "really important" for the Serie A side.
Ibrahimovic is back at Milan for a second time after returning to the Rossoneri – where he won the Scudetto in 2010-11 – at the end of his LA Galaxy contract.
The 38-year-old star has made an immediate impact, scoring in Milan's 2-0 Serie A victory away to Cagliari last week – only his second appearance.
Ibrahimovic was an unused substitute as Milan eased past SPAL 3-0 in the Coppa Italia last 16 on Wednesday, ahead of Udinese's league visit on Sunday, and Pioli hailed the striker amid the club's struggles.
"Signing Ibrahimovic has been really important," Pioli told reporters. "Absolutely, it's been really important for what he does every day during the training, for what he did at Cagliari and for what he will do.
"Ibra will improve giving us great satisfaction. He is so professional, he is so driven in all the things he does. It is unbelievable seeing a great champion like him working hard. It's important for a young team like us.
"After Cagliari he said to work hard and with passion so we can get a reward. This is the most important thing."
Without a Scudetto since Ibrahimovic's first spell, Milan are 10th in Serie A and 10 points adrift of fourth-placed Atalanta, while they are 23 points behind leaders Juventus.