The Memphis Grizzlies, a surprising 4-0 since losing Ja Morant to a knee injury, look to keep rolling Monday night against the host Miami Heat.

What the Grizzlies have done in the past week has been impressive. But it goes beyond being undefeated without Morant, who is one of the game's supreme talents. The Grizzlies have yet to even trail since losing Morant to what they believe will be a two-week injury.

One of those non-Morant games was Thursday's NBA-record 73-point win over the Oklahoma City Thunder. Memphis had a 15-point lead after the first quarter and a 36-point advantage at halftime.

On Saturday, the Grizzlies defeated the Dallas Mavericks 97-90 in another wire-to-wire victory. The Grizzlies led that game 49-37 at halftime.

"We've been getting off to good starts," guard Desmond Bane said. "We've been playing good defense, allowing us to run (in transition). That's our best offense."

Without Morant -- who is averaging 24.1 points and 6.8 assists -- the Grizzlies are getting balanced scoring from players such as Dillon Brooks (16.9), Bane (15.9) and Jaren Jackson Jr. (15.8).

Bane, for example, scored a career-high 29 points against Dallas.

Steven Adams leads Memphis in rebounds (8.2) while scoring 6.7 points. De'Anthony Melton, a key reserve who has also made 12 starts, is Memphis' other double-figure scorer (10.5).

Besides Morant, the Grizzlies have three important role players who are day-to-day due to injuries: Brandon Clarke (knee), Kyle Anderson (back) and Ziaire Williams (knee).

Tyus Jones, a 25-year-old former Duke star, has stepped in for Morant at point guard. Jones is averaging 6.7 points and 3.8 assists.

Meanwhile, the Heat have lost three of their past four games, including a 124-102 defeat to the host Milwaukee Bucks on Saturday night.

The Heat's issues at the moment appear to be mostly injury-related as two of their top three players have been out.

Bam Adebayo is expected to miss about six weeks due to a thumb injury and Jimmy Butler has missed four straight games due to a tailbone injury suffered on Nov. 27 against the Chicago Bulls.

Those two players have combined to earn six All-Star appearances, including five for Butler.

It's possible that Butler could return on Monday.

Even so, 21-year-old guard Tyler Herro has a massive responsibility on his young shoulders. Until Butler returns, Herro -- who is averaging 21.2 points -- is Miami's go-to scorer.

Two other keys to Miami's offense are point guard Kyle Lowry and shooter Duncan Robinson. Lowry is averaging 12.8 points and a team-high 7.6 assists. Robinson is averaging 11.0 points, but his 3-point percentage has dropped from 40.8 percent last season to 33.0 percent in this campaign.

Defensively, the Heat are looking for continued contributions from P.J. Tucker, a 36-year-old veteran who is averaging 6.6 points and 5.5 rebounds.

Tucker is a newcomer to the Heat this season after winning an NBA title with the Bucks last season.

"He's been a great fit," Heat coach Erik Spoelstra said of Tucker, who plays on the interior at 6-5 and 245 pounds. "We've been a fan of his for a long time."