Jeffrey D. Allred, Deseret News
Utah Utes quarterback Troy Williams (3)is tackled by Brigham Young Cougars defensive back Dayan Lake (5) in Salt Lake City on Saturday, Sept. 10, 2016.

PROVO — BYU's cornerbacks are sure to be tested when taking on UCLA this Saturday. Bruin quarterback Josh Rosen presents a different challenge for a Cougar defense that has yet to deal with a classic, drop-back quarterback so far this season.

Rosen will pair with a potent wide receiver corps with more deep throws likely coming the Cougar secondary's way.

"(He's) a really accurate quarterback, he has a strong arm and there's a lot of good playmakers on the outside," assessed BYU defensive coordinator Ilaisa Tuiaki. "They give you different matchup problems with their size and speed."

Defending against the Bruin passing attack will be a secondary without the services of safety Kai Nacua and cornerback Austin McChesney for the first half due to both players serving suspensions. The team also may not have the services of Troy Warner, who is nursing an injury.

The good news is that several other cornerbacks have stepped up, among them Dayan Lake and Chris Wilcox, both of whom saw several reps against Utah last week, along with Isaish Armstrong.

"They tested him a couple of times," Tuiaki said of Wilcox's first action against Utah last week. "Once they figured out he was a long enough corner who could run, I think they didn't want to test him. So for him to feel comfortable in that moment, and do what he did, I thought that was real maturing for him."

Langi still adjusting: Defensive end Harvey Langi is still adjusting to playing at his new position two games into the season, yet has shown good growth, according to Tuiaki.

"Everything is about technique for him," Tuiaki said. "His reactions to blocks is critical and he's coming along. He's along further than he was before, he still has a long ways to go, but he plays hard. I love watching him play. He's an awesome kid."

Twitter: @BrandonCGurney