To the best of our knowledge, there's only one Alex Stivrins who played in the NBA:

Alex Frank Stivrins: This Latvian-American forward played for a brief period in the NBA. Here are some interesting tidbits about him:

Drafted in the 4th round (75th overall) by the Seattle SuperSonics in 1985.

Played professionally for a few seasons in Europe before making his NBA debut in 1985 for the Sonics.

Considered the first ethnic Latvian (and Latgalian) to play in the NBA.

Had a short NBA career, with most of his success coming in European leagues where he averaged over 20 points per game in some seasons.

In 1992, he made a comeback to the NBA with the Atlanta Hawks, even playing against the first Latvian-born NBA player, Gundars Vētra.