It’s a big game for UCLA and USC when they meet on the court

As he watched his future rival dominate his future teammates game after game, TJ Leaf didn’t feel a surge of exasperation. He sensed opportunity.

“It wasn’t so much being angry, but just more excited just to come in and try to make an impact,” the UCLA freshman power forward said Tuesday. He was referring to USC’s dominance in the rivalry last season, when the Trojans won all three games in a season for the first time since 1942.

“Watching those games, I knew what we could be next year, so now I’m just excited to be in that moment.”

Across town, there is also enthusiasm about the possibilities. The Trojans can post a fourth consecutive victory over UCLA when they face the eighth-ranked Bruins on Wednesday night at the Galen Center. A victory would give them their longest winning streak against UCLA since they won four consecutive games from 2009 to 2011.

Recent history is heavily tilted toward USC in a series UCLA leads, 138-107.

The Trojans commemorated the historic significance of their season sweep at the Pac-12 Conference tournament in March when they wrote “1942” on the whiteboard inside their locker room along with “3-0.” Their 24-point drubbing of the Bruins that day was their biggest blowout in the rivalry in 71 years.

Of course, things can change quickly, as USC guard Jordan McLaughlin noted this week.

“We won the last three,” McLaughlin said. “They won the previous three before that.”

Actually, the Bruins had won the previous six games in the wildly vacillating series, going back to Coach Ben Howland’s final season with the team.

A victory Wednesday would have significance beyond ending or extending a streak. UCLA (19-2 overall, 6-2 in Pac-12 play) is vying for a No. 1 or No. 2 seeding and the possibility of remaining in California for the first two weeks of the NCAA tournament. Sacramento is hosting the first two rounds and San Jose the regional semifinals and final. A loss to the Trojans, with games against Oregon and Arizona still on the Bruins’ schedule, makes that scenario unlikely.

“It’s a big game for us,” UCLA shooting guard Bryce Alford said, “and it’s a big game for them.”

USC (17-4, 4-4) wants to avoid falling below .500 in the Pac-12 while solidifying its status as a team worthy of the NCAA tournament. The Trojans gave themselves some wiggle room after going 13-0 in nonconference play but have not beaten a ranked team.

USC won its games against UCLA last season by a combined 57 points, more or less running the Bruins out of the gym.

In the first meeting, forward Chimezie Metu, whom UCLA had passed over in recruiting, dominated with athleticism. Later, USC’s speed and length at home harassed the Bruins, who shot just 35%. In the Pac-12 tournament, the Trojans won every loose ball. The rebounding tally: 52-29 in favor of the Trojans.

After completing the regular-season sweep, USC Coach Andy Enfield was asked how his team had stifled the Bruins again.

“We have pretty good guards, too,” Enfield said.

It was as close as he’d ventured to a bravado since his controversial 2013 boast, “If you want to play slow, go to UCLA.”

This season, Enfield said, “Both teams are totally different.”

Arizona showed that a team athletic enough to run with UCLA and disciplined enough to defend at a high level can beat the Bruins, as the Wildcats did Saturday, 96-85, at Pauley Pavilion.

USC’s full starting lineup, were it available, would match up relatively well with UCLA. Metu gives Bruins counterpart Thomas Welsh athleticism issues. The Trojans guards have only improved defensively from last season’s smothering performances. And the matchup of USC’s Bennie Boatwright against Leaf would’ve been the game’s most interesting.

But Boatwright is out with a sprained knee and USC cannot replace him. Its options at forward, Charles Buggs (who is day-to-day with a sore knee) and Nick Rakocevic, each sacrifice athleticism to the players they will face. UCLA’s two forwards can exploit a four-guard set, but the Trojans often have no choice but to use it.

“I mean look on the bench and you have no big guys to put in,” Enfield said. “Who would you put in?”

Enfield hasn’t revealed how he plans to defend UCLA freshman point guard Lonzo Ball.

“I wouldn’t be surprised if we put Chimezie on him to start to use his length,” he said, smiling.

Freshman guard De’Anthony Melton, USC’s best all-around perimeter defender, is the most likely option. At 6 feet 4, he doesn’t have to worry about the 6-6 Ball towering over him.

When they played in a high school tournament in June 2015, Ball and Chino Hills prevailed over Melton and Encino Crespi, but Melton held his own. He scored 20 points to Ball’s 23. The most impressive stat was the final score: High-flying Chino Hills tallied just 70 points — modest, by its standards.

“He likes to shoot deep,” Melton said he learned from that meeting. “We’ve just got to keep our head on a swivel and contest all shots.”

The Bruins also discovered something as a result of being pushed around by their rival on the way to a rare losing season; there’s no need to dwell on a bad memory.

“We’ve just tried to move forward past everything that happened last year and just focusing on the now and what we have in front of us,” Alford said. “We are a much different team, but so are they.”

UCLA-USC TONIGHT

When: 8.

Where: Galen Center.

On the air: TV: FS1; Radio: 690, 570.

Update: UCLA literally turned up the volume in practice as a result of its feeble defensive effort while giving up 96 points against Arizona on Saturday during its first home loss of the season. “It was loud in here,” Bruins guard Bryce Alford said. “We’re so used to hearing the coaches talking in practice; [Monday], all I could hear was the players.” Alford described the Bruins as “a little bit embarrassed, a little bit upset and just ready to get back on the court” and said their desire was reflected in their best defensive practice of the season. UCLA needs drastic improvement because its defensive efficiency ranks No. 127 in the nation, according to statistics guru Ken Pomeroy. Virginia Commonwealth was the only team in the last 15 seasons to make the Final Four with a defensive efficiency ranking outside the top 80 when the Commodores ranked No. 81 in 2011. Meanwhile, USC has struggled offensively in Pac-12 Conference play without the injured Bennie Boatwright. The Trojans were last in the conference in shooting percentage through their first seven games, leading to lopsided losses on the road against Oregon and Utah and narrow home defeats against California and Arizona. Much of the Trojans’ offense comes from shooting guard Elijah Stewart, who is tied with point guard Jordan McLaughlin for the team lead with 14.1 points per game. McLaughlin also adds 5.1 assists per game. Forward Chimezie Metu is UCLA’s grittiest defender. He has averaged 14.5 points and seven rebounds in conference play.

ben.bolch@latimes.com

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zach.helfand@latimes.com

Follow Zach Helfand on Twitter @zhelfand