The 25-year-old has been tipped to swap San Siro for the Premier League or Barcelona for several months, while French champions Paris Saint-Germain have also been credited with an interest in his services.
Leao has established himself as a star player for Milan since joining the club from Lille in August 2019, scoring 59 goals and providing 54 assists in 221 appearances across all competitions.
The Portugal international, who was named Serie A Player of the Year in Milan's 2021-22 title-winning campaign, recorded 15 goals and 14 assists in 47 appearances for the Rossoneri last season.
This term, Leao has only scored one goal and has provided four assists in 11 matches for Milan across all competitions, and he has recently lost his starting spot under head coach Paulo Fonseca.
Barcelona keeping tabs on Leao's 'complicated and unexpected' situation
Indeed, Leao has been left out of Milan's starting lineup for their last two Serie A matches, watching on as an unused substitute in a 1-0 win over Udinese before coming on for the final 28 minutes in a 2-0 defeat to Napoli on Tuesday.
According to Spanish news outlet Sport, Leao is starting to become tired of his 'complicated and unexpected' situation at Milan, which has not been helped by his relationship with Fonseca.
The report adds that Barcelona are attentive to the situation of Leao, who is known to be a long-term transfer target for the La Liga leaders.
Leao is said to be a player who is admired by Barca's hierarchy, especially club president Joan Laporta, who attempted to sign the attacker in the summer after failing to lure Athletic Bilbao's Nico Williams to Camp Nou.
Could Barcelona sign Leao in 2025?
It is claimed that Barcelona will prioritise the addition of a new left winger in the summer of 2025 and Leao will become one of the club's top targets if an exit from Milan becomes a genuine possibility.
However, the Catalan giants will only step up their pursuit of Leao if they are quoted a 'reasonable' price for the attacker, who has previously been valued between €100m (£84.4m) to €150m (£126.6m).
After Milan's midweek loss to Napoli, Fonseca played down suggestions that his relationship with Leao has become strained, telling reporters: "There is no conflict with Leao.
"I decide as a coach and everyone must give their best. I must not beg anyone to give this maximum. Leao came on with a correct attitude against Napoli and there's nothing more to talk about."
Leao, who is under contract at San Siro until June 2028, will be hoping to force his way back into Milan's starting lineup when they face Monza in Serie A on Saturday and then Real Madrid in the Champions League three days later.