Jayson Tatum’s injury couldn’t have come at a worse time. And unfortunately, it’s the second time he has said such a thing in a year. Tatum ruptured his right Achilles tendon in early May during the second round of the 2025 playoffs amid a furious rally to try to tie up the Celtics-Knicks series at 2-2. And in Boston’s Game 6 loss against the 76ers, Tatum injured his left calf, which sidelined him in their 109-100 season-ending defeat , ending the Celtics’ 56-win season. “My recovery and comeback (from the Achilles injury) were going so well that how it ended, I didn’t think it was going to end that way. It was just unfortunate,” Tatum said Sunday after the game. “I worked really, really, really, really hard to come back in the fashion that I did and play at the level I was playing at. So for it to end the way it did was a tough pill to swallow.” Jayson Tatum sat out Game 7 with a leg injury.…