SAN FRANCISCO — Al Horford took his warmup shots with his son Ean and then sat in the locker room, open to reporters and took several questions. It’s a routine he did regularly while in Boston, and now performed in Warriors gear. And there’s still some uncertainty about why, with Golden State now 7.0 games behind the Celtics in the standings, Horford left the franchise he won his first championship and spent the most number of seasons with.

“For me, the decision, it’s something that’s deeper than just the basketball stuff,” Horford said pre-game on Thursday when asked by CLNS/CelticsBlog why he left. “It’s something that at some point I’ll share with people, but for me, it felt like it was the time for me to go elsewhere.”

Horford signed a two-year, $11.7 million contract with the Warriors late in the offseason after reports early in July pointed toward him departing Boston. Brad Stevens acknowledged later that the Celtics wanted to keep Horford and Luke Kornet, and made them offers, while noting that Boston’s limited flexibility by pointing to the minimum contracts they agreed to with other front court players.

His departure didn’t come without context around it though. Jayson Tatum’s Achilles tear nearly moved Horford to tears in the locker room following Game 4. Stevens signaled to Kristaps Porziņģis and Jrue Holiday following the Celtics’ defeat in Game 6 that they would probably move them for financial reasons during the offseason. An end of an era loomed, and while Horford reportedly weighed retirement among numerous options, Payton Pritchard stressed in his exit interview the importance of bringing Horford back.

Instead, reports almost immediately linked him to Golden State at the start of free agency, and after the deal became official after the Warriors’ nearly summer-long cap navigation, Horford expressed a desire to continue competing as a reason for joining Golden State. This week, he said Boston’s success came as little surprise.

“If you think about, even last year, we had a lot of guys down throughout the year, and we were playing a lot of the time missing a lot of players, and we were still winning a lot of games,” Horford said. “So I feel like that was a blueprint right there, and this year, I just think guys are comfortable playing in that situation and the biggest thing is everybody’s bought into what Joe is telling them and he’s just running a really good program over there, him and all those assistant coaches. They’re really doing a good job getting the guys ready, getting them to commit and play at a high level, and that’s why I feel like it’s so smooth. But I think if you look at last year, there were a lot of times that KP was out, Jrue was out, that different guys were out and we were still getting results. That’s why it’s not surprising of their success.”

Horford’s departure also surprised his father Tito when he found out about it over the summer, he told CLNS Media in October. He repeatedly called the decision one that was outside of Al’s control, and sources indicated at the time that Boston wasn’t able to offer more than a minimum contract to the veteran. Horford received two years of the taxpayer mid-level exception from the Warriors, where he’s averaged 7.6 points, 4.9 rebounds and 2.3 assists per game on 42.9% shooting (33.8% 3PT). Though a significant role also appealed to him, he only started five of his first 34 appearances with Golden State.

Porziņģis and Horford both came off the bench during Thursday’s loss to the Celtics, where the Warriors fell behind by as many as 34 points early in the third quarter. They rallied to within 11 points in the fourth behind the former Celtics’ contributions in a double-big look, Horford finishing with five points, eight rebounds and four assists on 2-for-10 shooting. After the buzzer, Joe Mazzulla found Ean for a photo, Celtics players greeted their former veteran and Horford admitted just how weird the experience proved.

The Warriors looked like a team figuring things out at an almost ground floor level. Boston more resembled a machine that’s played together for years. And while Horford remained committed to what they’re figuring out in Golden State, he didn’t rule out one more appearance in green before his career ends.

“As far as the end of my career, I don’t know,” Horford said. “I always keep that open. It would definitely be a privelage to do that, but I’m obviously so focused on trying to finish out this year.”