Arizona second baseman Kyle Lewis (28) fields a grounder from Eastern Kentucky’s Cornell Nixon (3) for the third out in the sixth inning in their game at Hi Corbett Field, Friday, February 17, 2017, Tucson, Ariz. Kelly Presnell / Arizona Daily Star

Kelly Presnell / Arizona Daily Star

Every so often, the tailback comes out in Arizona baseball coach Jay Johnson.

This is what Johnson, a former high school running back, had to say about the Wildcats’ defensive issues this season: “Good teams take care of the ball and limit scoring opportunities. We need to do a better job of that.”

In Johnson’s mind, errors are like turnovers. Arizona is giving the ball away too much this season – a trend that can’t continue if the Wildcats are going to contend in the Pac-12.

Arizona begins conference play Friday night with the first of three games at UCLA. A three-game series at Oregon State follows next weekend.

Only the fourth-ranked Beavers (14-1) had a better record than the 12th-ranked Wildcats (13-3) entering Thursday night. No league team had more errors (29) or a worse fielding percentage (.953) than Arizona.

As a result, the UA has allowed 21 unearned runs, the most in the conference. Oregon State had surrendered 24 total runs entering its Pac-12 opener at Arizona State on Thursday night.

“We have a saying: We won’t accept in winning what we would in losing,” Johnson said. “There’s things we have to improve on that we’re working hard on improving. Guys are getting exposed a little bit. We’ll keep cracking rocks.”

Arizona’s offense has masked its defensive inconsistencies thus far. The Wildcats led the nation in batting average (.357) and on-base percentage (.450) entering Thursday.

But Arizona will face better and deeper pitching in conference play. The Wildcats got a preview of it Wednesday night. Seventh-ranked Cal State Fullerton shut out Arizona, limiting the Wildcats to three hits.

UCLA (6-9) is off to a slow start and takes a four-game losing streak into Friday’s matchup. It isn’t for lack of pitching: The Bruins have a 2.98 team ERA and a legitimate ace in junior right-hander Griffin Canning.

Arizona counters with senior JC Cloney, who’s working with an entirely different infield from the one that helped the Wildcats reach the College World Series finals last year.

Two of this year’s regulars are freshmen: second baseman Cameron Cannon and third baseman Nick Quintana. They have combined for 14 errors.

“You’re going to go through those phases as a freshman,” senior infielder Kyle Lewis said. “It’s testing them right now, so we’re going to see what they’re made of. I think it’s a good thing.”

Lewis has taken over as the starting shortstop with fellow senior Louis Boyd out of the lineup because of a left-arm injury. Boyd had gotten off to an unusually rocky start defensively with four errors, but he stabilized the defense last season and provided continuity this year amid all the other changes. His presence also enabled Johnson to platoon Lewis and Cannon at second, easing the pressure on the freshman. Boyd is expected to be about another month.

Johnson used upperclassmen Seve Romo and Sawyer Gieseke as late-inning defensive replacements against Hartford on Sunday. But the only path to real improvement is through repetition and experience.

Arizona worked on infield fundamentals before batting practice Sunday morning. The Wildcats are going to keep working at it until they get it right.

“It’s been a rough patch,” Lewis said. “But I think if you keep sticking with it, it’ll take care of itself. We’re taking those baby steps that I think can make a big difference.”

Inside pitch

• Johnson on opening Pac-12 play at UCLA and Oregon State: “You’re talking about the two kingpins of the Pac-12 over the last 10 years on the road in the first two weekends. We’re trying to build a program that will catch up with those guys.”

• Canning hasn’t figured in a decision, but he ranks first in the Pac-12 in opponent batting average (.138), second in strikeouts (38, in 28 innings) and third in ERA (0.96). He also has a 0.89 WHIP.

• Cloney ranks fourth in the conference with a 1.00 ERA . He has won all four of his starts and has walked only four batters in 27 innings.

• Junior outfielder Mitchell Morimoto’s 15-game hitting streak to start his UA career ended at Fullerton. Junior first baseman JJ Matijevic has reached base in all 16 games.

Matijevic and junior outfielder Jared Oliva were tied for the national lead in doubles (11) entering Thursday.

Sophomore right-hander Michael Flynn (2-0. 1.40) is slated to start for Arizona on Saturday. Sunday’s starter is TBA.