The Celtics and Heat “have engaged in the most advanced trade talks” with the Bucks as the Giannis Antetokounmpo sweepstakes moves into its presumed home stretch, according to Marc Stein of The Stein Line (subscription required).

After his latest report was published early Monday morning, a league source told Stein that Boston emerged from the weekend “with a real shot” at landing Antetokounmpo with an offered centered around Jaylen Brown (Twitter link). Stein adds that Milwaukee is considering a deal with the Celtics even if a third team can’t be found to facilitate it.

The other details of Boston’s offer remain murky, but Stein notes that it would likely include young talent and future draft assets. He hears that Milwaukee has interest in Hugo Gonzalez, the team’s first-round pick from last season.

A sticking point could be draft compensation, as the Bucks are known to be seeking another lottery pick for Tuesday night to go with their own selection at No. 10. Boston is slotted at No. 27, so finding another team willing to part with such a pick while taking on Brown’s salary of $183MM over the next three seasons would improve its chances of acquiring the two-time MVP.

More to come …