The Heat, who lost to the New Orleans Pelicans 124-123 in overtime on Friday night, have lost eight of their past nine games, putting the franchise in danger of missing the playoffs.
Miami (30-29) is a defensive-minded team, ranking third in points allowed, although some of that has to do with their slow pace of play (28th out of 30 teams in that category).
On Friday, the Heat defense was victimized by Pelicans superstar Anthony Davis, who had 45 points, 17 rebounds, five blocks and five steals. Miami also couldn't stop point guard Jrue Holiday, who had 29 points, nine assists and seven rebounds, including the game-winning runner with 7.3 seconds left in overtime.
Those performances overshadowed solid efforts by Heat point guard Goran Dragic, who nearly had a triple-double with 30 points, nine rebounds and eight assists; and center Hassan Whiteside, who had a double-double with 19 points and 16 rebounds before fouling out.
"We have to forge ahead regardless of what emotions we're feeling," Erik Spoelstra told the media after the Pelicans loss. "All these moments can benefit us, and I truly believe they will. We are so close to getting over the hump."
The Heat will be facing an 18-39 Memphis team that has been out of playoff contention for several weeks.
Injuries have crushed the Grizzlies, who lost their eighth straight game on Friday night, falling 112-89 to the Cleveland Cavaliers.
Grizzlies point guard Mike Conley (heel) is gone for the season, having played only 12 games, and wing Chandler Parsons (knee) has been severely limited.
The Grizzlies, who will miss the playoffs after qualifying for seven consecutive years, have seen their 14 players miss a combined 175 games due to injury or illness this season.
That situation could be made worse by the time they arrive in Miami since guard Tyreke Evans left the Cleveland game midway through the fourth quarter due to a rib injury.
"We may have our shortcomings," Grizzlies interim coach JB Bickerstaff said in a massive understatement told to the Commercial Appeal, "but our effort and competitive nature are still there."
The Heat, meanwhile, are trying to get healthy. Center/power forward Kelly Olynyk, who has been in the rotation all season as either a starter or key reserve, has a shoulder injury but is expected to return within days, possibly in time to face Memphis.
Small forward Rodney McGruder won't play against the Grizzlies. But he has been sent to the G League, meaning his return to the NBA after suffering a left-leg injury in the preseason is close at hand.
The plan is for McGruder -- who started 65 of his 78 games last season -- to play with the Sioux Falls SkyForce Saturday and Monday and then return to the Heat on Tuesday.
"More weapons -- that's what we need down the stretch," Heat shooting guard Wayne Ellington told The Sun-Sentinel.
"I think (the return of injured players) will be great for us. It will elevate some of our games. When you have a little more pressure to perform, that will make our team better."