07:19 AM ET 07.04 | On the Wednesday evening before a long holiday weekend, the Celtics announced Butler's Brad Stevens would become their next head coach, seemingly out of the blue. But in truth, Danny Ainge's first thoughts turned to [Stevens] two Sundays ago, at roughly the same time Doc Rivers' departure for the Los Angeles Clippers was finalized. According to a league source, that's roughly when Ainge approached Stevens, who finally made the decision yesterday to become the 16th head coach in Celtics history. He will be introduced at a press conference tomorrow morning. And he'll be here for a while. The 36-year-old agreed to a six-year, $22-million contract, according to a league source.