Trailing by two with 12 seconds left, Carter ran into a log-jam South Florida defenders and missed a forced jumper that could have forced overtime in a 67-65 loss.
"The last play is definitely a shot to the gut but a lot of plays led to that," said coach Mike Rice after the loss on WCTC's post-game shot.
On the defining play, USF's Anthony Collins knocked down a runner and drew a foul on Gilvydas Biruta to make it a three-point play. Following Collins' free throw, Rutgers failed to win it on the final sequence.
Rutgers battled back from an eight-point deficit thanks to the play of Carter and Mack. Carter led Rutgers in scoring with 23 points, after exceeding 40 minutes just three days ago. Off the bench, Mack scored 14 points on 5-of-8 shooting.
Freshman forward Derrick Randall put up his second consecutive strong game off the bench. The big man scored 10 points and had five rebounds.
"He's doing something with a five that we haven't had here in two years," Rice said. "We're getting production, we're getting toughness. ... Probably look for him in the starting lineup in the very near future."
Freshman forward Malick Kone made his return to the court after missing December with a knee injury. Kone missed time after arthroscopic knee surgery and logged seven minutes in his first game back.
After three minutes of action against Florida, red-shirt freshman forward Kadeem Jack played five against USF and blocked his first career shot.
Rutgers (8-6, 0-1) returns to the Louis Brown Athletic Center Wednesday and hosts West Virginia in its Big East home-opener.