Brad Stevens was shocked.

Sure, the Celtics head coach had heavy input before Boston’s trade for Kyrie Irving last summer, but the reality of a deal with the Cavaliers coming together in August — roughly one month after Irving requested a trade from Cleveland — still stunned Stevens.

“First of all, I didn’t think (the trade) was happening and then, in about a 20-hour period, it went from, ‘I didn’t think it was happening’ to, ‘Holy smokes, this might happen,'” Stevens recently told ESPN’s Chris Forsberg.

The Celtics eventually traded Isaiah Thomas, Jae Crowder, Ante Zizic, the Brooklyn Nets’ 2018 first-round pick and the Miami Heat’s 2020 second-round pick to the Cavs in exchange for Irving.

It was a trade Boston’s front office was excited about — “Everybody, unanimously, wanted to do it,” Celtics president of basketball operations Danny Ainge told Forsberg — but there still was a bittersweet element to the whole process: Breaking the news to Thomas, who had become the heart and soul of the Celtics in his two-plus seasons in Boston.

“The range of emotions were really wild because you would have no thought that Isaiah Thomas would ever be a part of a trade,” Stevens said, per Forsberg. “I thought, with Isaiah, that was really hard. I’ve talked about the emotional investment that you have as a coach and a player, and working together every day, and that’s why I’ve said that I don’t think I could do the front office because those hard decisions — I do not envy those. …

“The only way you would even consider doing that is for a person of Kyrie’s caliber. But that doesn’t make it any easier.”

Last season was interesting for both the Celtics and Cavaliers, who met in the Eastern Conference finals for the second straight year, with Cleveland ultimately advancing to the NBA Finals in seven games. Thomas didn’t debut with the Cavs until Jan. 2 because of a hip injury and appeared in just 15 games with Cleveland before being shipped to the Los Angeles Lakers at the NBA trade deadline. Irving, meanwhile, missed the end of the regular season and Boston’s entire playoff run after undergoing knee surgery.

But the trade still is being felt across the NBA, especially with LeBron James since leaving the Cavs, Irving now returning to a Celtics team that looks destined to contend for a title and Thomas settling for a veteran’s minimum contract with the Denver Nuggets after prior speculation about him potentially signing a max contract.

Shocking, indeed.

Thumbnail photo via Erik Williams/USA TODAY Sports Images