Denmark captain Kjaer has been at the seven-time European champions since January last year after signing from Sevilla. The defender has become a fan favourite among the red and black half of Milan. His great performances and leadership have earned the Danish international a contract extension until June 2024.
Kjaer has played 66 times for Milan and was named in the 30-man shortlist for this year's Ballon d'Or. As well as Kjaer's defensive displays next to Tomori that took AC Milan back into the Champions League, the center-back's Euro 2020 performances lead Denmark into the Euro's semi-finals.
AC Milan's next game is against Mourinho's Roma away on Sunday, another chance for Kjaer to prove himself.