Danny Shelton noticed. He couldn’t help but notice. At one point in Washington’s 44-30 loss to UCLA on Saturday, the senior defensive tackle looked around and assessed all the talent not on the Husky Stadium field with him.

The 2014 Huskies were built around four stellar defensive playmakers, but for much of this game, Shelton was the only one on the field. Cornerback Marcus Peters is gone, for good, having been kicked off the team last week. Linebacker Shaq Thompson is now the offense’s most dependable weapon, and he has played sparingly on defense the past three games. And now defensive end Hau’oli Kikaha, who leads the nation with 16.5 sacks, is hurt. He suffered a shoulder stinger early in the game Saturday and didn’t return.

For all their struggles this season, the Huskies (6-4) have a winning record because of their big-play defense, highlighted often by the individual talents of those four elite players, all of whom are expected to be playing in the NFL next season. They have wreaked havoc — sacks, tackles for loss, fumbles, interceptions, touchdowns. The Huskies aren’t a great defense overall, but they have done great things because they have great players.

But the Saturday sunset felt like a fade to black for the terrific foursome. Now it’s just a two-and-a-fourth-some with Peters gone and Thompson barely on defense. And against UCLA, it was often just Shelton.

“We never expected any of this,” Shelton admitted afterward. “We couldn’t have known this would happen to our defense. It’s just about how we react now, really. We had a slow reaction in this game, and we can’t let that happen. We can’t back down one bit.”

No. 18 UCLA exploited the diminished Washington defense, gaining 476 yards and scoring 31 of its 44 points in the first half. Quarterback Brett Hundley threw for 302 yards and two touchdowns and ran for two more scores.

The Huskies played better in the second half. Only 161 of the Bruins’ 476 yards came after halftime, and Washington outscored UCLA 20-13 over the final two quarters. But the early damage made a comeback impossible.

It was frightening to watch the defense without Kikaha. He injured his shoulder sacking Hundley during the game’s first series. UCLA was forced to punt, and you saw a potential opening for the Washington defense to give the Bruins trouble. But when Kikaha — who had recorded a sack for the 14th consecutive game — exited, so did the Huskies’ hopes of a consistent pass rush.

The Huskies already were without Thompson’s ballhawking and Peters’ coverage skills. Now, they couldn’t make the opposing quarterback uncomfortable. For the first time this season, the defense looked woefully vanilla.

Washington had been anything but vanilla this season. The defense has given up plenty, because of a young secondary and poor tackling and some missed assignments, but the Huskies have been an aggressive, attacking unit. They have scored seven defensive touchdowns. They have 38 sacks, second in the Pac-12. They have forced 20 turnovers, twice as many as they have committed on offense.

But without three of those stars for most of the game, the Huskies had to play a more passive style. They were careful. They played a lot of zone, which is necessary when three true freshmen now are starting in the secondary. They couldn’t get good pressure with the four defensive linemen, and they didn’t blitz much. Their best hope was to play it safe and challenge the Bruins to mount long drives against them. UCLA was able to do that, and Hundley also connected on a big play, hitting Kenneth Walker III for a 57-yard TD in the first quarter.

“We’ve got to be able to make teams earn things,” coach Chris Petersen said. “We can’t just give them easy things.”

Like Shelton, Petersen recognized the limitations on defense. Add that to an offense with a feeble passing game and a dependence on Thompson in the running game, and the Huskies couldn’t rely on anything, really.

“Certainly, when you’re taking Hau’oli out of the mix and Shaq out of the mix, those are a lot of the playmakers on one side of the ball,” Petersen said of the defense. “It makes for tough sledding.”

When your best defensive player also is your best offensive player, it makes for tough sledding. Petersen inherited some top-shelf talent, but he also took over a weird mix of experience and inexperience, star power and significant holes. Now the coach is trying everything possible — Thompson at running back, John Ross at cornerback — to mask deficiencies by leveraging his best athletes.

Right now, though, attrition and experimentation are minimizing what makes the Huskies special. The elite foursome now is a threesome, at best. And Kikaha, the most consistent member of the group, is ailing.

Petersen has been on a never-ending search for identity all season. The closest thing to an identity is the Huskies’ random greatness on defense.

If those big plays decrease, this weird, transitional season could have an ugly ending.

Jerry Brewer: 206-464-2277 or jbrewer@seattletimes.com

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