(Photo credit: Sam Navarro-Imagn Images)

The Boston Celtics knew they were headed to the playoffs, and now it's official for the defending champions.

One night after becoming the third Eastern Conference team to clinch a postseason berth, the Celtics hope to continue to trend upward on Saturday evening when they visit the Brooklyn Nets.

The Celtics (48-19) clinched their latest playoff berth with a 103-91 win over the host Miami Heat on Friday.

Boston is 6-1 over its past seven games.

Jayson Tatum scored 28 points against the Heat to continue a surge in which he has averaged 32.1 points over his last seven games.

Tatum and the Celtics were without Jaylen Brown due to a nagging knee injury. Brown has missed 13 games with various ailments, is 39-for-98 from the field over his past five games and may be out again Saturday.

Jrue Holiday helped compensate for Brown's absence by scoring a season-high 25 points. He hit a season-best five 3-pointers and is coming off his fourth game with at least 20 points after dealing with a recent finger injury.

'Tonight was a good day,' Holiday told NBC Sports Boston in an on-court interview. 'Sometimes when I catch, it feels weird, but there's no excuses out here. They don't care that my finger's broken or I have mallet finger, so I'm just trying to come out here every game and focus in and try to lock in.'

The Celtics are 12-1 in the past 13 regular-season meetings against the Nets after earning two wins in a span of six days in November. Nine of their victories in this run over the Nets are by double digits, including their 139-114 rout in Brooklyn on Nov. 13, when they shot 53.8 percent from the field and sank 22 3s.

After the Celtics rallied for a 108-104 overtime home victory on Nov. 8 in the first meeting, Brown scored 24 in Brooklyn after sitting out the first encounter. Tatum scored 20 of his 36 in the second half of Nov. 13, when the Celtics outscored the Nets 107-80 over the final three quarters.

The Nets (22-44) are attempting to slow the Celtics after losing nine of their previous 10 games.

Brooklyn's past four losses -- against the Chicago Bulls, Cleveland Cavaliers, Charlotte Hornets and Golden State Warriors -- are by a combined 16 points due to struggles in the second half. In those games, the Nets were outscored 241-189 while committing 66 fouls, resulting in 64 free throws.

'It's kind of easy to (get upset) when you lose double-digit leads multiple times in the fourth quarter, just poor execution, poor shot-making, poor defense time after time,' Brooklyn's Cameron Johnson said. 'It wears on you. So we've got to figure out how to combat that and shake those types of performances off and learn from them and learn how to get better

In Thursday's 116-110 loss at Chicago, the Nets held a 10-point lead after three quarters and were outscored 34-18 in the fourth.

Cam Thomas scored 24 points Thursday and is 16-for-47 from the field after halftime in the past four losses, including a 4-of-14 showing in the final two quarters in Chicago.

--Field Level Media