In a film session between Games 4 and 5 of their Eastern Conference semifinal series, as the Celtics prepared for their first game against the New York Knicks without Jayson Tatum, veterans Jaylen Brown and Al Horford challenged the remaining members of the team to rally for their injured superstar.

The Celtics, behind 22 3-pointers and a breakout game from big man Luke Kornet, stayed alive in the NBA postseason, beating the Knicks on Wednesday night in Boston, 127-102.

Knicks guard Jalen Brunson sent well wishes to Jayson Tatum after the Celtics star underwent Achilles surgery on Tuesday.

The Celtics would have to stage that rare comeback without their best player in Tatum, who suffered a torn Achilles at the end of Game 4. His teammates stepped up in his absence Wednesday, with Derrick White scoring 34 points and Jaylen Brown adding 26 points and a postseason career-high 12 assists.

During an appearance on ESPN's "NBA Today," NBA insider Marc J. Spears shared details of an emotional conversation between Tatum and his father following the devastating injury. According to Spears, Tatum asked his father, "Why me, dad? Why me? Why does this have to happen to me?"

Jayson Tatum's heart-wrenching conversation with his father, Justin, immediately after he went through his Achilles injury, was shared by an NBA insider.

Jayson Tatum heard it all after the Celtics blew Game 2 to the Knicks. After a bounce-back performance, he spoke about the perspective needed when it comes to being Boston's top player.

Meanwhile, Tatum, who is 12 for 43 in this Knicks series overall (including 5 of 20 from 3), has missed eight of 10 shots and all four of his 3-pointers in 19 clutch minutes so far in this postseason. It's an extension of a regular season in which he shot 6 for 31 from 3 and just 65% from the free-throw line during clutch minutes.