The Red Bulls, who had the best regular-season record in the MLS this season, announced the signing Wednesday without releasing details of the contracts.
Acquired from Portland before the season, Alexander appeared in every regular-season match, recording personal highs in games played (34), starts (30), goals (4) and shots (33). Alexander also played in two playoff games and scored a goal.
Kimura was also acquired in the 2012-13 offseason from Portland. The full-back played in 24 games (15 starts) and had two assists.
Luyindula was signed in March after previously playing for Paris Saint-Germain. He made 22 appearances (9 starts) and had one goal and seven assists.