That change, along with a stellar game from forward Robert Thurman off the bench, provided some much-needed pop as the Golden Bears broke a three-game losing streak by downing UC Santa Barbara, 68-59, in front of 6,489 at Haas Pavilion.
Thurman scored a game-high 14 points, becoming the first player other than Crabbe and Cobbs to pace Cal (7-3) in scoring this season. He added six rebounds, four on the offensive glass.
Thurman was especially active in the first half, scoring four points during an 8-0 run late in the first half that pushed the lead to 13. It was the sort of production that head coach Mike Montgomery has been seeking from his front line all year, and still came away less than thrilled.
"We should have been able to score at the block," Montgomery said. "We still have not established how we are going to get shots and what we are going to get down in there. David (Kravish) ends up with 10 points, but I thought David was passive. Robert will finish shots inside and he did a good job."
In another critique of his front line, Montgomery was quick to point out that Wallace's 10 rebounds were a team-high, adding 10 points for his first career double-double.
Wallace had been working with the first unit extensively in practice, but wasn't informed that he would start until earlier in the day. After a sluggish start, missing his first four shots, he found his rhythm in the second half.
"A lot of it is just confidence," Wallace said. "I have confidence in my abilities and I know what I can do."
"He's smart, he is savvy, and he can finish it well for a freshman," Thurman said.
Montgomery wasn't sure if moving Wallace into the starting five would be permanent going forward. Perhaps more importantly, he doesn't believe it would bother the Bakersfield (Calif.) product either way.
"I don't think he thinks about things like that. I think that's why he is effective," Montgomery said. "He isn't looking at the bench. He just goes out and plays. If there is a ball, he goes and tries to get it and that is where he really helps us."
Apart from Wallace, Montgomery didn't have much positive to say about anyone or anything, likely because of the late run by the Gauchos (4-6) to cut a 22-point lead into single-digits for the final margin. They did so by raining three-pointers, making 13-of-30 from behind the arc to make up for forward Alan Williams being held to eight points.
Williams came into the game averaging 17.2 points per game, and it was the first time this season he did not finish with double-digits.
"They go around the big man in the middle, and if that doesn't go for them, they are going to jack up the threes," Thurman said. "We knew they were going to do that, but it was easier said than done to stop them. Guys would have hands in their face, hard contested shots and they were just pulling up and making them."
That negated advantages everywhere else on the court, as Cal was plus-24 points in the paint, plus-10 on the fast break, and even plus-seven in bench production.
"We did try to emphasize trying to keep them from getting the three, and they end up getting 13 of them, which was the only way we thought they could beat us," Montgomery said. "They ended up getting some pretty good shots."
That was not the case for Crabbe, who finished with 12 points but made only 4-of-12 shots from the field, still visibly rattled by his 6-of-26 performance against Creighton.
Said Montgomery: "Saturday bothered him, and he has just got to play his way through it."
Dan Greenspan writes about the Pac-12 for Fox Sports Next. Follow him on Twitter @DanGreenspan.