The Celtics were unable to regain the lead in the NBA Finals as they lost Game 5 against the Warriors in San Francisco.

Game 6 will be played on Thursday in Boston and it will be a do-or-die situation for the hosts. Al Horford understands the importance of this game and says it will be a test of his team’s character.

“Definitely we weren’t as sharp as needed to during times there,” the 36-year-old center said. “It’s just tough. Definitely I know now our backs are against the wall. We have to see what we’re made of. The challenge starts back home on Thursday.”