The 26-year-old Gutierrez most recently played in Canton of the NBA Developmental League, where he averaged 15.2 points, along with six assists and five rebounds, over six games. He spent parts of this season and last season with the Brooklyn Nets.
Gutierrez, who played in college at California, is reuniting with Bucks coach Jason Kidd, who was with Brooklyn last year. Kidd also played at Cal.
Gutierrez fills a roster spot following the suspension Jan. 16 of center Larry Sanders for violating the league's substance abuse policy. Sanders has missed five games of what the NBA said would be at least a 10-game suspension.