Arizona Wildcats center Kaleb Tarczewski (35) reaches over Skylar Spencer of San Diego State University to make the basket in the first half during a game at Viejas Arena in San Diego, California. Photo taken Thursday November 14, 2013 Photo by Mamta Popat / Arizona Daily Star

Mamta Popat / Arizona Daily Star

The streak was supposed to be over before it started, really.

Just three games into its season, Arizona went into rowdy Viejas Arena and hung on to beat now No. 5-ranked San Diego State, thanks in part to four Nick Johnson free throws in the final minute.

That was one thing. Then there was the NIT Season Tip-Off in New York, and the semifinal scare against Drexel that suggested Arizona would have no business beating Duke two days later, which, of course, the Wildcats did.

“That was the first sign that maybe we have a good team,” UA coach Sean Miller said.

After that, it was Michigan, a cross-country road game played just three days after UA hosted New Mexico State. Another win.

Then, into the new year, you could have figured it would all end at UCLA, which beat UA three times last season.

“I really felt especially with how hard to win in L.A., and last year losing to UCLA … I don’t know if everyone was picking us there, either,” Miller said.

So what now? Stanford? Cal?

It’s easy to suggest that Stanford, with a crew of talented veterans, or California, with healthier players and coaching wizard Mike Montgomery, could end the Wildcats’ 20-0 run.

But … it’s complicated.

Here’s why:

The Bay Area can be tough.

After all, it’s where the Wildcats’ 1997 national champions were swept the weekend before they began that memorable run that included wins over three No. 1 seeds.

Arizona’s 1988 Final Four team, and its 30-7 team in 2004-05, also suffered losses at Stanford, while even a UA win in 2000 at Maples Pavilion was bittersweet because Richard Jefferson broke his foot.

… But it really isn’t, historically.

Even during Montgomery’s best years at Stanford, the Cardinal often fared better at McKale Center than at Maples and, in recent years, the Wildcats have been living easy at both Bay-Area venues.

In fact, Lute Olson had what turned out to be his last coaching win at Stanford, an overtime thriller on March 3, 2007, while Miller has lost only once in three previous trip to the Bay — a 95-71 downer at Cal during his first season in 2009-10.

Arizona even won at Cal in triple overtime in 2010-11, despite losing star Derrick Williams to a foul-out in regulation — and knocked off the NCAA-tournament-bound Bears the following season, too.

The games mean everything to Cal and Stanford.

With an RPI of 53, Stanford is currently sitting on the NCAA tournament bubble. That also means its coach, Johnny Dawkins, is sitting on a hot seat, depending on how you read into the remark of Stanford AD Bernard Muir last spring that “we clearly have set the expectation that we want to be playing at this time of the year” when he decided to bring Dawkins back for a sixth season.

At Cal, the Bears are one of the few teams who appear capable of challenging Arizona for the Pac-12 championship. But a loss to UA (assuming Cal and Arizona win on Wednesday) would put the Bears three games behind, with their only other shot at the Cats being at McKale Center next month.

“The meaning of these two games for them is immense,” Miller said.

But … Miller says the games are also significant for Arizona.

That is, if the Wildcats intend to win the Pac-12 this season. They don’t want to lose at Cal and be just a game up on the Bears with five more road games to go.

Nor do they want to lose at Stanford, which could get back in the Pac-12 race if it can sweep this weekend.

“I’ll tell you, they better not sleep on Stanford,” Montgomery said. If they do “they won’t have to worry about (the streak) with us. Stanford’s playing good, and they’re a good team.”

Stanford and Cal can hit the boards.

It sounds boring, but it’s true. If there’s one key that’s become increasingly obvious to beating the Wildcats, it’s the need to rebound.

Arizona fires up its lethal transition game with defensive rebounds. On the offensive boards, Arizona makes up for any shooting problems by grabbing the ball time after time (20 times, in fact, against Utah, making up for 40-percent shooting in UA’s 65-56 win).

“It’s imperative that you’re dialed in on the glass” against Arizona, Utah coach Larry Krystkowiak said. “We got them to miss a fair amount of shots, but we were poor on the defensive glass. You can’t (give up) 20 offensive rebounds.”

Both Stanford and Cal are among the Pac-12’s top-four teams in defensive rebounds in conference play, while Stanford is actually grabbing 73 percent of its defensive rebounding opportunities — far ahead of Arizona’s 68.2 percent rate.

“Stanford’s a very talented team,” Colorado coach Tad Boyle said. “They have some size and athleticism where they can maybe compete (with Arizona). I’m not saying they’re gonna dominate, but they can compete.”

… But UA is even better.

On the more difficult offensive boards, Arizona is simply dominant. The Wildcats lead the Pac-12 in pulling down 39.2 percent of their offensive rebounding chances in conference games and in averaging 13.0 offensive boards per game.

Although Arizona failed to outrebound two of its four previous opponents, the Wildcats had a convincing 40-29 rebounding edge against Utah.

“We’re best when we get out on the break, hitting spot-up threes and getting to the rim, so that all starts with getting defensive rebounds,” UA guard Johnson said. “Over the last few games, we haven’t been doing that ... so we are just getting back to our identity on defense and finishing the possession.”

The Wildcats aren’t great shooters.

Arizona ranks ninth in Pac-12 games in three-point shooting at 32.4 percent after putting together a combined 6-for-29 effort from long range against Colorado and Utah last weekend. The Wildcats also hit less than 30 percent against both WSU and Washington, and just 33.3 percent at UCLA.

Their free-throw shooting, meanwhile, has gotten worse in conference play. It’s only 65.0 percent in Pac-12 games, the 10th worst mark in the league.

All that suggests a down-to-the-wire game that calls for a big shot or free throw — could be scary.

… But Arizona has a clutch shooter in Nick Johnson and makes its mark on defense.

Johnson hit a big three late in the game against Duke, and his free throws sealed wins at San Diego State, Michigan and UCLA.

In addition, Arizona has been taking the need for clutch shooting away by simply making it worse for the other teams’ offenses. Against Utah, for example, the Wildcats held the Utes to 39.1-percent shooting in the second half and to just one field goal over the final 6:50, and a tie game with 10 minutes to go became a nine-point win.

“The thing that’s tough with Arizona is they defend so well, and that’s not going anywhere,” Washington coach Lorenzo Romar said. “That is something they can sustain. So if you come out against them and you’re not really knocking down shots, it’s going to be a long night.”

The pressure is on Arizona.

No active Pac-12 coach knows more about unbeaten streaks than Montgomery. His Stanford teams ripped off 18 straight to start the 1997-98 season, 20 to start 2000-01, and 26 in 2003-04.

That life wasn’t easy. The 2003-04 team managed to go 17-1 in Pac-12 play before losing at Washington in the last game of the regular season.

“I felt the pressure, and I tried to keep it away from our guys,” Montgomery said. “You don’t think about it along the way; you’re just hoping to win the next game. But when we got to the very end, where we were one or two wins away from the first team being 18-0, it was there. You just couldn’t deny it. I tried. But I felt it. Whether the players felt it or not, I don’t know.

“I’m sure Sean’s saying the same things — ‘We’ve got this next game and we’re not even thinking about it’ — but the longer you go, the more it becomes a reality, and the more it sneaks into your subconscious.”

… But there’s not that much heat yet.

While Montgomery’s Cardinal felt the pressure in 2003-04, and UA may have when it went 16-0 in league play in 1997-98 before an overtime loss at USC, this season’s Wildcats aren’t even halfway through the conference season, with seven more road games to go.

So maybe they can keep their heads down and focus on tonight, then on Saturday’s game, and on staying ahead in a conference they let slip away last season.

Besides, before this unbeaten thing started, that’s what the Wildcats really wanted to do.

“For us, it’s about our performance and being the best we can be and staying with what we’ve done that’s gotten us to this point,” Miller said.

“Our goal is not to be undefeated as much as compete for that Pac-12 Conference championship.”

Sportswriter for the Arizona Daily Star covering Arizona Wildcats basketball