Jets WR Brandon Marshall says it's obvious former NBA star Delonte West needs help ... and he believes it's the duty of the NBA to reach out and give him the treatment he needs.

TMZ Sports broke the story ... West was recently seen at a Houston fast food joint in the middle of the night, without shoes, looking pretty disheveled. 

Marshall -- who's been very vocal about overcoming his own mental health issues -- was at LAX when we asked about West's seemingly dire situation ... and who could help. 

Check out the clip -- Brandon says he definitely thinks Delonte needs a helping hand ... and that the NBA could -- and should -- do their part to reach out to guys having tough times.