When Mack Tuck was hired this summer to coach the Rizing Fukuoka, he took over a team that had reached the bj-league championship game in May but fell one victory short of its ultimate goal. The Rizing, then coached by Atsushi Kanazawa, lost to the Yokohama B-Corsairs in the title match.

Now, Tuck's tenure as head coach is apparently over before it every really began. He was in Japan during the preseason but departed before the team's opener on Oct. 5, a 91-76 road win over the Takamatsu Five Arrows. But, according to a team source, he left Fukuoka due to a family matter.

He hasn't returned.

On Tuesday, Kimitoshi Sano, who began the preseason as Tuck's assistant, was promoted to head coach. The 31-year-old Sano was the Miyazaki Shining Suns' second head coach in 2012-13, taking over for bench boss Junichiro Hongo, who stepped down after the team's 4-26 start. Sano, originally Hongo's assistant, remained at the helm until the end of the season, finishing with a 5-17 record as coach. (Miyazaki left the bj-league after the season; the franchise now plans to enter the NBDL, the rebranded JBL2, for the 2014-15 campaign.)

It appeared, however — at least until Tuesday — the door was open for Tuck's return to the Rizing bench, according to a source familiar with the situation.

"I guess they were waiting to see if (Tuck) was coming back," a team insider told The Japan Times on Tuesday.

That's no longer the case.

Sano's promotion is the first official coaching change in the 21-team league this season.

Sano has remained in charge of the team in Tuck's absence. Through Sunday, the Rizing (5-7), who have lost six of their last eight games, sit in seventh place in the 10-team Western Conference. (The top six teams in each conference advance to postseason play.)

Tuck, who resides in Texas, was an assistant coach for the Chinese Basketball Association's Shandong Lions under former NBA bench boss Bob Weiss (2009-11). He then served as the Shandong junior team's head coach in 2011-12.

Tuck, a former star player in China, did not respond to multiple email messages left by this newspaper.