UPDATE: Since Al Horford‘s original claim that playing against the Celtics in their first-round series was unrealistic, the Hawks center has changed his tune. A consultation with his surgeon resulted in a prognosis that he could return to the court on Thursday in a limited role, according to the most recent Yahoo! Sports report.

“It remains to be seen what I can bring,” Horford told reporter Marc J. Spears. “But I hope to bring some scoring. They can’t expect a lot from me defensively because it’s been a while since I’ve even played. That’s one of the things that will hold me back, but scoring I can help. And also with presence with the team in general.”

It’s official. When the NBA’s Eastern Conference playoffs begin at month’s end, the Celtics will face the Hawks — the same team that in 2008 took them to seven games in the first round. That was then, when the championship nucleus of Paul Pierce, Kevin Garnett and Ray Allen was just finding its groove. This is now, five years later.

The first four of this core’s 43 playoff wins came against Atlanta, but will its last also come against the Hawks?

The first time around, the home team won all seven games in the series, but that advantage is yet to be settled this season. The Celtics (37-27) own the tiebreaker but trail Atlanta (38-26) by a game. While neither of the C’s final two opponents has much motivation left (the Heat have an outside shot at the No. 1 seed, but the Bucks have been eliminated), the Hawks host the Clippers and Mavericks — both still jockeying for playoff position out West.

Regardless, this promises to be a different series, full of fresh faces. Case in point, Avery Bradley was a junior in high school the last time these two teams met in a playoff game. Now, he’s replaced Allen in the starting lineup.

On the Celtics side, Garnett, Pierce and Allen remain, and Rajon Rondo has developed from the perceived weak link five years ago to a three-time NBA All-Star. In two games against the Hawks this season, he has averaged 16.5 assists, 10.0 points and 6.5 rebounds, including a triple-double on April 11. Everyone else from 2008 is gone.

The Celtics backcourt's defense against Joe Johnson should be a major factor against the Hawks. (AP)

The Hawks started Joe Johnson, Josh Smith, Al Horford, Mike Bibby and Marvin Williams five seasons ago. Jeff Teague has since replaced Bibby as the team’s starting point guard, and as for Horford, Yahoo! Sports reporter Marc J. Spears tweeted, “He does not expect to play in the postseason due to pectoral injury.”

“I don’t feel like it is realistic that I can play for the playoffs,” Horford told Spears. “Obviously, if we advance and start going we will see. But as of right now the way I feel I think I am out for the playoffs.”

Celtics nemesis Zaza Pachulia replaced Hoford as Atlanta’s starting center, although he’s missed the last five games and remains day-to-day with a sprained left foot. Kirk Hinrich took over the starting shooting guard duties, moving Williams into a Sixth Man role alongside stalwart Ivan Johnson and a revolving door of Jannero Pargo, Willie Green, Tracy McGrady, Vladimir Radmanovic and Jason Collins off the bench.

Meanwhile, the Celtics are also awaiting good news on injuries to Allen (ankle) and Mickael Pietrus (knee), who have missed seven and three straight games, respectively. The C’s remain hopeful both will be healthy for the playoffs, forming a tight eight-man rotation with Greg Stiemsma as the backup big behind Garnett and Brandon Bass. Keyon Dooling might see some minutes, but don’t expect much from anyone else.

The Celtics will enter the series with a 2-1 record against the Hawks in three tight games this season. The C’s won the first two meetings, 79-76 and 88-86 (OT), and even gave Atlanta a run for its money in a 97-92 loss while Doc Rivers rested Pierce, Rondo, Garnett, Allen and Pietrus. But let’s dig a little deeper.

Celtics (rank) … TEAM OFFENSE … Hawks (rank)
98.6 (25th) … Points Per 100 Possessions … 101.3 (17th)
45.9 (5th) … FG% … 44.9 (14th)
36.4 (6th) … 3P% … 36.5 (5th)
77.9 (5th) … FT% … 73.8 (23rd)
23.6 (1st) … Assist Rate … 21.2 (8th)
14.8 (26th) … Turnover Rate … 13.4 (10th)
20.1 (30th) … Offensive Rebound Rate … 24.0 (25th)

Celtics (rank) … TEAM DEFENSE … Hawks (rank)
95.2 (1st) … Points Allowed Per 100 Possessions … 98.5 (6th)
41.6 (1st) … FG% … 44.2 (11th)
29.7 (1st) … 3P% … 33.7 (8th)
28.7 (19th) … Free Throw Rate … 24.9 (6th)
17.5 (1st) … Assist Rate … 19.6 (14th)
14.5 (5th) … Turnover Rate … 14.3 (6th)
72.5 (21st) … Defensive Rebound Rate … 74.3 (8th)

Really, an argument could be made for either team as the superior offense. Atlanta scores more, hits the offensive glass harder and turns the ball over less frequently, but the Celtics shoot more efficiently from the field and the free throw line while ranking atop the NBA in passing.

However, there is no debate over which squad owns the better defense. While the Hawks might be improved since years past, the Celtics rank first in the league in opponents’ points per 100 possessions, field goal percentage, 3-point percentage (a bonus against a team that attempts 5.1 more treys per game) and assist rate. The number of free throws Celtics opponents attempt also indicates a more physical style of play.

Oversimplifying, if the C’s can rebound and take care of the ball, home court shouldn’t matter, so free agents Allen and Garnett won’t have to watch the same team that opened this playoff window be the group to close it. After all, Bovada lists the Celtics at 16-1 to win the NBA title — significantly better odds than the Hawks (75-1).

(Have a question, concern or conception for tomorrow’s Irish Coffee? Send a message to @brohrbach on Twitter.)