“Because I know what I can do,” Horford said. “I know what I am and what I can bring to a team. I was just thinking to myself: ‘When I get an opportunity, I’ll show that I can still play. That I’m fine. That I’ll be good.’” Horford hurtled past good Monday night and built a home on great. He said a switch flipped inside him after Giannis Antetokounmpo punctuated one dunk with a glare in Horford’s direction. The act resulted in a technical foul for Antetokounmpo. More than the single free throw the snarl gave Boston, the bigger impact came from the motivation it lit inside Horford. “I don’t really know what he said to me,” Horford said. “But the way that he was looking at me and the way he was going about it really didn’t sit well with me.”