Question: In their 72nd season this NBA team aquired an American professional basketball player who was named NBA Rookie of the Year in what year?
Sentence (from "2017–18 Boston Celtics season"): The Celtics will play the first game of the regular season on October 17, 2017 against the Cleveland Cavaliers, Irving's former team, and retire the number 34 of former small forward Paul Pierce on February 11, 2018 against the Cavs.
Relevant evidence: No