SPOKANE, Wash. -- Former Gonzaga men's basketball All-Americans and NBA rookies Domantas Sabonis and Kyle Wiltjer will join fourth-year veteran Kelly Olynyk as each made their respective team's 15-man rosters announced Monday.

After going undrafted, Wiltjer used a stellar preseason with the Houston Rockets to cement his position on the roster. In six preseason games, Wiltjer averaged 8.3 points in 14.8 minutes per game. He added 2.7 rebounds per game. Wiltjer made 41.7 percent of his shots from three-point range. The Portland, Ore. native, shot 47.5 percent from the field.

Sabonis averaged 23.5 minutes per contest in six preseason games for the Oklahoma City Thunder. The 11th overall pick in the 2016 NBA Draft scored 6.5 points per game, making 48.4 percent of his shots from the field. He also grabbed 2.7 rebounds a game, while dishing out 15 assists during the preseason.

Olynyk returns for his fourth season with the Boston Celtics. He is averaging 9.6 points and 4.7 rebounds through his first three seasons. He has played 203 games as a Celtic after being the 13th overall selection in the 2013 NBA Draft. Olynyk averaged 10 points and 4.1 rebounds per game last season.

The trio begins their NBA seasons Wednesday. The Celtics host Brooklyn at 4:30 p.m., while the Thunder travel to Philadelphia and Houston visits the Lakers in an ESPN doubleheader that begins at 5 p.m.