Tabuse had been training with Japan's national team but decided to leave the squad and head to the United States after receiving an invitation to attend the Dallas Mavericks' summer camp next month.
"I got the news all of a sudden and am happy I was able to get another opportunity," Tabuse said at a news conference Saturday.
Tabuse, 28, played briefly for the Suns in the 2004-05 season and is the only Japanese player to make it to the NBA.
The 5-foot-9 point guard joined the Suns' training camp in 2004 and made the opening-night roster. He scored seven points in his first NBA game against the Atlanta Hawks but was waived by the Suns on Dec. 16, 2004.