WALTHAM — The Celtics aren’t in the easiest spot right now. They’re banged up. They’re getting outworked and they’re down two games to a Miami Heat team that many consider the odds-on favorite right now to capture the NBA title.

But alas, not all hope is lost. Just ask Glen Davis, who Thursday at Celtics practice had a chance encounter with a Celtics legend of the past who told Davis to just hang in there. After all – as the Ringo Starr song goes – It Don’t Come Easy. Just like John Havlicek told Davis.

“The frustration, things not working out, you can get all messed up. But I was talking to Havlicek today, you know, ‘Havlicek Stole the Ball’ and I said which one of these [championship] banners were you 0-2, and he said the one that stood out to him was 1969. When they were down 0-2, they came back to win it in Game 7 against the Lakers.”

That was the series, of course, that featured the Don Nelson shot that bounced straight up after hitting the back of the rim and came down through the net at the old Los Angeles Arena to put the Celtics on top and lead them to their 11th title with Bill Russell in the organization. It also marked the only time the Celtics ever won a series after losing the first two games.

“He was just saying, ‘It’s going to take everything in you to fight and claw back and get back to get to 2-2 even but then it’s going to take something special to finish them off.’”

Can they do it against the Miami Heat? Davis said Thursday after practice that getting back to the mental and physical toughness that makes the Celtics a great team would be a good place to start.

“We didn’t play Celtics basketball,” Davis said. “Nobody played the way they were supposed to play. Ray had a good game the first game but we still didn’t pull it off. We all were supposed to play well but we didn’t. It’s easy to point the finger and blame and play the blame game as Kanye West would say but you’ve got to go get it. That’s all it is right now. X’s and O’s and you can coach as much as you want but that still ain’t going to make it happen.”