By Baxter Holmes, Globe Staff

The free-falling Celtics have dropped six straight and just blew a 27-point lead to Atlanta. They're quickly losing their grip on the No. 8 spot in the Eastern Conference -- the last available playoff spot, mind you -- and their coach is short on solutions.

So, what perfect timing for a showdown with the reigning champions and a homecoming rematch of last season's epic Eastern Finals showdown, a series that may seem like yesterday for Miami fans but certainly feels like eons ago for Celtics faithful.

Oh, and Ray Allen is back in town.

STARTING LINEUPS

BOSTON CELTICS (20-23)
PG Rajon Rondo
SG Avery Bradley
SF Paul Pierce
PF Brandon Bass
PF Kevin Garnett

MIAMI HEAT (28-12)
PG Mario Chalmers
SG Dwyane Wade
SF LeBron James
PF Udonis Haslem
C Chris Bosh

TV/RADIO: 1 p.m. ABC / WEEI (93.7)

Pregame notes:

• Allen is returning to Boston for the first time since he left the team to sign with the Miami Heat last offseason. The man fondly known as "Jesus Shuttlesworth" joined Boston in 2007, played in two Finals and won one with the team, but he did join a team that has ended the Celtics' season in each of the last two seasons. Expect mixed reactions from the Garden when Allen's name comes over the loudspeaker.
• This is the second of four meetings between these clubs this season. Led by 29 points from Wade and 26 from James, the Heat took the first game in Miami, 120-107, in the season opener Oct. 30. Allen scored 19 off the bench.