TUCSON, Ariz. – At the start of the season, the Washington State Cougars were supposed to be the team rich with offensive prowess, while the Arizona Wildcats were supposed to be the ones trying to find an identity.

Scratch that. The Wildcats have one. The Cougars are still searching for theirs.

The final result at Arizona Stadium Saturday night left a handful of exclamation marks for the offense on the home sideline and produeced just as many question marks for the one on the visiting sideline.

The Air Raid didn’t play up to par. The “Speed D” was even worse.

After letting Arizona’s turbo-charged quarterback, Khalil Tate, waltz up and down the field to the tune of 146 rushing yards, the Cougars now have just six days to solve their defensive shortcomings before they face the only player capable of beating Tate for Pac-12 Offensive Player of the Year.

And they have to decide on a starting quarterback – potentially the last issue WSU thought it would encounter when the season began a few months ago.

But the first priority is diagnosing what went wrong on both sides of the ball Saturday in the desert, where the Cougars all but wilted in a 58-37 loss to an Arizona – a preseason pick to finish last in the South that’s looking more and more the part of a conference title contender.

“We played dumb against a really good team,” WSU coach Mike Leach said.

The Wildcats became bowl-eligible, improving to 6-2 overall and 4-1 in the Pac-12. The Cougars, now 7-2 and 4-2, lost ground in the race for the Pac-12 North, but it’s nothing they with games against Stanford and Washington still looming.

“It’s a testament to this team that we can lose two games – two close to the end of the season – and our goals are still in front of us,” WSU senior running back Jamal Morrow said. “So that’s one good thing about this. We still have an opportunity to be in the Pac-12 championship. We’ve just got to go out there and take care of business.”

There just isn’t much room for error now.

On Saturday, the mishaps were wide-ranging – not exclusive to any one facet of the game.

WSU starter Luke Falk, never quite in rhythm, led the Cougars into the end zone just once in his first seven drives. Five times, they were forced to punt. Another drive culminated with a missed field goal.

Leach decided the offense needed a jumpstart and made the gutsy move to pull Falk, his fourth-year starter, and insert the backup, Tyler Hilinski. The stunt worked for a moment – Hilinski led a nine-play, 75-yard touchdown drive capped by a 6-yard keeper to bring the Cougars within six points – just not in the long-term.

“I wanted (Luke) to see the field, I didn’t think he had his best stuff,” Leach said of the decision to swap QBs. “I think he was trying to do way too much, we weren’t pushing the ball upfield. I wanted him to watch Tyler because I figured he’d execute pretty well and wanted him to see how simple it was, but then Tyler got really hot so we stuck with him.”

Hilinski rushed for two touchdowns and passed for two more, but had more than a few reckless plays, throwing four interceptions and nearly fumbling on another occasion.

It was late in the second quarter when Leach replaced his record-setting senior with the redshirt sophomore second-stringer. Hilinski got WSU into the end zone, but the Cougars gave up 50 yards on the ensuing kickoff and Arizona kicker Lucas Havrisik knocked in a 56-yard field goal as time expired to give the Wildcats a 23-14 lead at the break.

Leach stuck with No. 3 in the second half, while No. 4 stood on the sideline, only able to offer moral support to the Cougars, and a few tips to the guy running the offense in his place.

Hilinski had some good moments, finishing 45-of-61 through the air with 509 yards. By comparison, Falk was 13-of-23 with 93 passing yards. But Hilinski shot the Cougars in the foot more than once with his errant throws – and this wasn’t a day in which the WSU defense could recover.

“I felt like we were executing on offense,” Hilinski said. “Everybody was doing their jobs, besides the turnovers. Offensive line played their butts off tonight. … Some critical plays where I made mistakes is what it came down to.

“I think I was just trying to do too much, trying to make it all happen in one play.”

The Cougars trailed by as many as 13 points in the half, but despite closing the gap, were still outgained 281-192 by the Wildcats and their sophomore phenom QB.

Tate slipped free for a long run of 84 yards in the second quarter – it was his fourth run of 70 yards or longer in four games – and sped in from 49 yards out early in the fourth quarter.

In total, WSU conceded 310 rushing yards and four touchdowns on the ground. The Wildcats had an explosive play in each of the four quarters and took advantage of every defensive breakdown on a night in which the Cougars had many.

“We didn’t execute,” safety Rob Taylor said. “Missed assignments. We’ll watch film and get back to it tomorrow.”

Arizona had explosive plays of 43, 48, 42, 82, 45, 62, 69, 49 and 68 yards. Tate or Taylor had a hand in all nine of those. The Wildcats QB will have a chance to win Pac-12 Offensive Player of the Week award for the fourth week in a row.

“They blew coverage, their eyes were in a bad place, they blew run gaps,” Leach said. “Like I said, I thought they played hard but dumb. They’ve got to play smarter than that. It’s very easy. Here’s your gap, have that gap. Get the call, line up, go to your gap. It’s easy.”

Tate’s become one of the country’s most explosive runners – and he’s easily the top rushing QB in college football – but he also made WSU pay with his arm, completing 10-of-17 for 275 yards and two touchdowns.

The Cougars did a fine job of bottling him up as a rusher in the early stages, but couldn’t sustain it.

Jalen Thompson pinned Tate in the backfield on the game’s opening play for a loss of three yards, but the UA QB unleashed a 43-yard downfield pass to Shawn Poindexter to put the Wildcats in WSU territory. But Tate was unable to scramble to the first-down marker on third down and Arizona would settle for a 30-yard Josh Pollack field goal.

The Wildcats forced a three-and-out on the Cougars’ first offensive series and extended their lead when Tate spied his tight end open downfield and then hit Jamie Nunley for a 48-yard score.

Luke Falk and the WSU offense couldn’t make it to midfield on their next drive, and looked like they’d be giving the ball back to the Wildcats for a third time, but Arizona’s Shun Brown muffed Kyle Sweet’s punt and the Cougars took over on the opponent’s 25-yard line.

Six plays later, they were in the end zone. Falk threw a bullet to Isaiah Johnson-Mack on the goal line to cut the Arizona lead to 10-7.

The Cougars could’ve tied the score at 10-apiece when they rolled out kicker Erik Powell to try a 56-yard field goal. Powell’s boot had the distance but sailed wide left.

Instead, Arizona continued to pad its lead. Tate went deep to Tony Ellison for a 41-yard completion, then hit Brown on a sideline screen for a 17-yard TD, making it 17-7.

Tate registered his fourth run of 70 yards or longer on the next play, but what was initially ruled an 86-yard touchdown came back when referees decided Tate had stepped out at the 2-yard line. The Cougars played stout defense and held the Wildcats to a field goal.

But Arizona broke the seal in the second half, outscoring the Cougars 36-23.

“That’s a great team, they executed and we didn’t,” Taylor said. “That’s the bottom line.”