Hayward's reported decision to opt out came minutes before Thursday's 5 p.m. deadline.
Unfortunately for Hayward and the Celtics, things didn't exactly go as according to plan as Irving eventually left the Celtics in free agency, all while the Celtics were subjected to some disappointing playoff exits.
Extending the deadline does not guarantee Hayward will ultimately opt in.
The Knicks have been aggressively pursuing Hayward for weeks, according to Marc Stein of the New York Times. It began with a horrifying leg injury that ultimately required multiple surgeries. However, should Hayward decline his option because of Boston prioritizing Tatum, Brown and Kemba Walker over him, they'll have steep competition for his services.
Hayward might prefer to be traded to another team that would be considered more of a contender than the Cavaliers, who have won only 19 games in each of the last two seasons. After joining the Celtics in 2017, signing a four-year max contract after spending his first seven National Basketball Association seasons with the Utah Jazz, Hayward suffered a gruesome foot and ankle injury six minutes into his first game with the Celtics that October.