The book is closed on the Hawks’ 2015-16 regular season.

And the last two pages did not end well at all.

The Hawks prepare for the NBA playoffs after losing big to the Cavaliers, a potential second-round opponent, and the Wizards, a team without four starters, in their final two games. The final defeat cost the Hawks a third-place finish in the Eastern Conference, a Southeast Division title and a later matchup with those top-seeded Cavaliers should they advance that far.

Next up for the fourth-seeded Hawks are the fifth-seeded Celtics in a best-of-seven first-round series which begins Saturday with Game 1 in Atlanta. The Hawks’ final regular-season win came against the Celtics here last week. So, there’s that.

“For us, it’s just about moving ahead and focusing on the Celtics now,” Al Horford said after the finale loss to the Wizards Wednesday.

The Hawks and Celtics — and the third-seeded Heat and sixth-seeded Hornets — all finished with 48-34 records in the jumbled conference standings for seeds Nos. 3-6. The Hawks held the head-to-head tiebreaker, 3-1, over the Celtics and the Hornets. The Hawks at least know they’ve had some success against the Celtics. The Heat held a 3-1 head-to-head tiebreaker over the Hawks, including a win in Philips following the All-Star break without Dwyane Wade, Chris Bosh or Hassan Whiteside. There is the difference between third and fourth place.

The Celtics earned the fifth seed after it appeared they were about to end the regular season with a fourth consecutive loss. They trailed the Heat by 26 points Wednesday, but rallied for a win after outscoring the Heat 25-5 in the third quarter.

To a man, the Hawks said that they are not worried about any lingering effects of their bitter loss to the Wizards.

“I’m not concerned about us coming out like that in the playoffs,” Kyle Korver said.

There is some history between the Hawks and Celtics.

The Hawks have faced the Celtics in seven playoff series since moving to Atlanta. They are 0-7. Count the four series when the Hawks played in St. Louis, and the record is 1-10. But these teams are a long way from a Dominique Wilkins versus Larry Bird duel or a Zaza Pachulia forehead-to-forehead battle with Kevin Garnett.

After a Nov. 13 loss in Boston (106-93), the Hawks won at home Nov. 24 (121-97), on the road Dec. 18 (109-101) and at home April 9 (118-107). The Hawks’ average margin of victory in those three wins was 18 points.

However, the Celtics present problems. They have an All-Star guard in Isaiah Thomas. They use a variety of lineups. They have several offensive and defensive schemes aimed at confusing an opponent. And, like the Hawks, they want to play up-tempo.

Here are some outlooks from the Hawks on the series:

Coach Mike Budenholzer: "Offensively, they do a lot of things that are a little different, a little unique. Isaiah Thomas has played extremely well this year, so we have to make it difficult on him. I think we've got to execute against them offensively. They are a good team. I think we both know each other well.

Jeff Teague: "They are a good team. They junk up the game and make it an up-tempo game. They play all kinds of crazy lineups. It's going to be a battle."

Korver: "It's going to be a good series. They are a tough team, a well-coached team. They'll throw all kinds of lineups out there. They have a lot of athletic, good guards. They are a very smart team that doesn't beat themselves. We are going to have our hands full."

The Hawks also will see a bit of themselves in the Celtics.

Celtics coach Brad Stevens candidly said before the final regular-season game against the Hawks that he has borrowed from other teams and coaches — including plenty from the Hawks’ playbook.

“I’ve stolen more from Budenholzer than a lot of people,” Stevens said before last week’s game. “I love the way he runs his stuff. I love the way he runs his sets at the end of games.”