Just one game into this year's NBA Cup, the Boston Celtics are already facing an uphill battle in their quest to make it to Las Vegas. The Celtics were completely outplayed by the Atlanta Hawks on Tuesday night,

The Celtics got the loss Joe Mazzulla said they deserved after they were "outplayed (in) every facet" against the shorthanded Hawks.

Hawks Surprisingly Defeat Celtics in Tight NBA Cup Match

Fueled by an impressive 35 assists as a team and one of Jayson Tatum's best games of the season (36 points, 9 rebounds, 10 assists), Boston also got great games from Jaylen Brown (24 points, 12 boards) and Jrue Holiday (16 points, 6 rebounds, 3 steals) among the starters.

The Celtics enter this matchup after a 117-116 loss against the Atlanta Hawks on Tuesday in which Boston wasn't able to overcome an Atlanta team missing its best player in Trae Yo

Jaylen Brown went for 37 points, but the Boston Celtics still fell to the Atlanta Hawks 117-116 to open the NBA Cup.

On Tuesday night, Boston Celtics head coach Joe Mazzulla walked into his pregame press conference with a sweatshirt that featured the word “MINDSET” in a large, bold font. He donned the same sweatshirt after the Celtics were stunned by the shorthanded Atlanta Hawks,

Jayson Tatum finished with 20 points, six rebounds, eight assists, one steal and two blocks while shooting 5/16 from the field and 2/9 from the three-point range in 37 minutes. Many NBA fans reacted to his performance.