Mack played roles in two key turnovers, and missed his most important shot of the game. The result was a blown nine-point lead and loss to UCF, the No. 9 seed in the conference.
"It's a tough loss, very tough," said Rutgers coach Eddie Jordan on the WCTC postgame show. "We just had to make plays at both ends of the floor. You can't give up dunks. You can't give up layups."
Rutgers led by 15 with nine minutes left in the game when UCF got hot and the Scarlet Knights' defense fell apart. UCF standout Isaiah Sykes flew through three defenders for an uncontested layup to take the lead in the final minute.
After trading fouls, a missed J.J. Moore three-pointer locked up a fourth straight Rutgers loss.
"When you come down to your need plays for the last four minutes, we didn't trust it enough," Jordan said. "… We just didn't finish."
Mack finished with 19 points, but committed five turnovers in the loss. Freshman Junior Etou fell one rebound short of a double-double with 14 points.
Jordan did not make changes to his starting lineup after saying he planned to go with a similar look to the Memphis game. Foul issues for Wally Judge and Malick Kone hampered the rotation in the second half, and led to more time for Moore on the court.
The Scarlet Knights (10-18, 4-11) now need significant help for the final first-round bye in the American with three games left. South Florida is next on tap, looking to avenge a home loss to the Scarlet Knights earlier this season.