Ball will take the spot of Brooklyn Nets forward Kevin Durant, while Murray will sub for Golden State Warriors forward Draymond Green. Durant is recovering from a sprained MCL in his left knee, and Green has a lower-back disk injury and said last week that he would miss the All-Star Game.
The league also announced that Boston Celtics forward Jayson Tatum will take Durant's place as a starter. Per NBA rules, a starter has to be replaced by the reserve from the same conference and same position group (backcourt or frontcourt) who received the highest ranking in the voting for All-Star starters. That's what gave Tatum the nod.
Durant will still participate in the All-Star draft as a captain alongside Los Angeles Lakers forward LeBron James. Durant and James will select their All-Star teams on Thursday.
Ball, the NBA Rookie of the Year last season, entered Tuesday averaging 19.6 points, 7.5 assists and 7.1 rebounds this season. The 20-year-old was also selected to take part in the Rising Stars festivities.
"I'm pretty much blessed, excited," Ball said before the Hornets faced the Toronto Raptors on Monday night. "The season is still going on, the game is going on. I'm just worried about the game."
Hornets coach James Borrego called it "exciting news."
"Happy for Melo, happy for his teammates," Borrego said. "I think they need to share this together. They've done this together and I know they're extremely happy for him, proud of him, as am I as his coach. Thrilled for our organization."
Murray, 25, is averaging 19.6 points, 9.2 assists, 8.4 rebounds and 2.1 steals this season -- numbers that no player has reached during a single season in NBA history. He is looking to become just the third player to average eight assists, eight rebounds and two steals in a season, joining Magic Johnson and Michael Jordan. He is also second in the league this season with 10 triple-doubles, trailing only Nikola Jokic.
Information from The Associated Press was used in this report.
The highlights that make LaMelo Ball an All-Star
Check out LaMelo Ball's top plays from this season as he gets ready to compete in his first All-Star Game.