What are Boston's next moves if Kyrie and Horford walk?

Kim Klement/USA TODAY Sports

Where do the Boston Celtics stand with Al Horford prepared to join Kyrie Irving as an unrestricted free agent after declining his 2019-20 player option?

Reporting Tuesday by ESPN's Adrian Wojnarowski confirmed a breakdown in talks between Horford and the Celtics, leading him to prepare to test free agency for a long-term offer elsewhere.

Meanwhile, Boston awaits word about Irving's future amid growing evidence he plans to leave. (Wojnarowski reported recently there is strong mutual interest between Irving and the Brooklyn Nets.) And Anthony Davis is no longer an option for the Celtics after the New Orleans Pelicans agreed over the weekend to trade him to the Los Angeles Lakers. So where does that leave Boston this summer? Let's take a look.