who is the person that contributed to napheesa collier's injury last season

It was Alyssa Thomas who was directly involved in the play where Napheesa Collier was injured in the WNBA semifinals last season; Collier appeared to twist her ankle after being knocked down following a steal by Thomas.

What happened

Collier’s injury came late in Game 3 against the Phoenix Mercury, and reports described it as an ankle injury that kept her out for Game 4.

Important nuance

That doesn’t necessarily mean Thomas “caused” the injury in a malicious sense — it was part of a live basketball play.

If you want, I can also give you the exact game context and what the broadcasters/reporters said about the play.