LOS ANGELES — A whiteboard sat stationary Tuesday on the sideline of the upstairs practice court at the Galen Center, permanently smudged black and ugly from wear, separated into two simple columns.

“Turnovers,” read the left-hand side of the board, with subhead designations: “Gold,” and “Card,” short for “Cardinal.” “Offensive Rebs” read the right-hand side, with the same subheads. For weeks, since the midway point of the season, head coach Andy Enfield and USC’s coaching staff have wheeled this whiteboard out at practice, keeping track of total turnovers when players are split into two separate teams – “Gold” and “Cardinal” for competitive drills.

Across a trip to Arizona in late January, playing without primary ball-handlers Boogie Ellis and Isaiah Collier, USC coughed up the ball a total of 41 times in two games. An “alarming rate,” as Enfield put it Tuesday. So staff started adding a caveat to team-against-team drills in practice: Not only could you lose two points by giving up a basket, you could lose two points by turning the ball over.

“Then if you lose the game, whatever drill we’re in, then you have to run – well, it’s not really punishment,” Enfield cracked, part of an explanation when asked about punishment for turnover tallies. “It’s just extra wind sprints.”

The tallies, and wind sprints, have worked. Getting Collier and Ellis back has helped, too. USC’s turned the ball over more than 10 times just once in their past five games; freshman Collier, in particular, has progressed leaps and bounds as a floor general and decision-maker.

Now, uh, for the other side of the board.

At the beginning of the month, after getting dominated on the glass by UCLA and Oregon, Enfield didn’t hold back on his bigs’ inability to rebound consistently – “they’re just not good defensive rebounders,” he said Feb. 1. And USC simply hasn’t improved since, despite making clear strides offensively and defensively. They’ve been outrebounded handily for four consecutive games, swallowed whole in last Saturday’s loss to Colorado, a near-unbelievable 47-22 deficit on the boards.

“This has been very, very much an Achilles heel for our team,” center Joshua Morgan said after Tuesday’s practice.

An Achilles heel, except Greek mythology holds that Paris fired just one arrow at the demigod, and these Trojans have taken volleys, game after game. Tracking rebounds on that whiteboard, thus far, hasn’t paid off. The reason why is elusive; rebounding is an incredibly difficult skill to teach, requiring a certain amount of instinctual grit and individual effort, and despite solid positional size, USC finds itself outrebounded on the year and close to the bottom of the Pac-12 as a result.

“We love this team as individuals,” Enfield said Tuesday, part of a response when asked if he felt his team needed more toughness in rebounding. “They’re great – really nice young men that work hard. They’re trying to be tough. But the rebounding thing is not necessarily natural for a lot of guys. They’re just not natural rebounders. So, trying to work on that right now, and hopefully we can make improvements.”

The timeline has grown razor-thin. USC (10-16, 4-11 in Pac-12) heads to Pauley Pavilion on Saturday night for a rematch with the Bruins (14-12, 9-6), a similarly struggling program that simply outmuscled them to a 43-29 rebounding edge a month ago at Galen Center, and has since been on a 5-1 stretch.

A mere five games and two weeks remain before a trip to Las Vegas for the Pac-12 tournament – the Trojans’ last chance at an NCAA tournament berth, a sobering reality that senior DJ Rodman said set in after Feb. 10’s blowout loss at Stanford.

It was a different feeling, Enfield said Tuesday. For three consecutive years, USC has made March Madness on an at-large bid. The coach whipped out USC’s record the past four seasons, somehow apparently at the tip of his tongue: 95-36 (it’s actually 95-38, but close enough).

“We’re not used to losing close games,” Enfield said, because crunch-time defense would carry them.

They have not been able to close this year, their record 3-9 in games decided by 10 points or less, because they haven’t been able to rebound. And thus, their last hope lies through a Pac-12 gauntlet, amid nightclubs and weirdness in Vegas. It’s still attainable – if they could simply crash the glass.

“We were one of the favorites to win in the beginning of the year, and I mean, we still have the same team,” Rodman said, “so I don’t know why that’s not a possibility.”

USC at UCLA

When: 7 p.m. Saturday

Where: Pauley Pavilion

TV/radio: ESPN/790 KABC