The Hawks announced Monday they fired Lloyd Pierce after two and a half seasons but didn't lay out their succession plan.
Beyond his preexisting rapport with the roster, McMillan is a natural replacement in the middle of the regular season because of his NBA coaching experience prior to joining the Hawks.
He has had spells with the Seattle Supersonics, Portland Trail Blazers and Indiana Pacers and boasts a 661-588 career record. His exit from Indiana upon the conclusion of the 2019-20 campaign came as a bit of a surprise as the Pacers finished 45-28 despite not having Victor Oladipo for most of the year.
The Hawks were aggressive in the offseason, adding Danilo Gallinari, Rajon Rondo and Bogdan Bogdanovic. They also got to see Clint Capela on the court after he didn't appear for the team to close out last offseason following his trade from the Houston Rockets.
Pierce's ouster speaks to a level of frustration that the team is 11th in the Eastern Conference at 14-20. Now, McMillan is tasked with salvaging Atlanta's playoff hopes.
As much as having a different voice leading the coaching staff might help, simply getting the roster healthy again will likely provide the biggest boost.
De'Andre Hunter hasn't played since Jan. 29, and Bogdanovic has been out even longer (missing the last 25 games). Rondo and Gallinari, meanwhile, have combined to make 40 appearances.
Hunter underwent a lateral meniscus arthroscopic debridement procedure on Feb. 7, with general manager Travis Schlenk setting seven to 10 weeks as the tentative window for his return. Bogdanovic, meanwhile, seems closer to a return after having been listed as questionable for Tuesday's game against the Miami Heat.
The danger for the Hawks is the team's performance in the second half may not be fully indicative of McMillan's influence. You'd expect some level of improvement with Hunter and Bogdanovic both back regardless of the coach.
That McMillan only has the interim tag seems to indicate the front office is still open to pursuing more long-term solutions in the offseason, when it has more time to evaluate the coaching landscape.