The 21-year-old who lost his leg during a car accident involving Haywood Highsmith earlier this month is now suing the NBA player ... claiming the hooper's careless driving caused the entire tragedy.
Alekxei Pino filed the lawsuit on Friday in Florida ... alleging he was helping assist a stranded motorist on Feb. 6 in Miami when Highsmith barreled into him in his 2021 Audi A5 at a high rate of speed.
Pino claims in the suit Highsmith was going over the roadway's legal speed limit before he hit him .