Matthew Stafford has faced just about every kind of defensive challenge during his NFL career. But one young Cardinals cornerback gave him a problem that stood out to Mike LaFleur.

LaFleur saw it firsthand while serving as the Los Angeles Rams’ offensive coordinator in 2025. Now Arizona’s head coach, he was discussing Will Johnson’s rookie season when he revealed why Johnson could be such a difficult player to figure out.

Cardinals reporter Tyler Drake reported that LaFleur said Stafford “didn’t like playing against Will Johnson last year.” The reason? “You don’t really know what Will’s going to do.”

“I was really impressed with Will as a rookie. Obviously, I didn’t study him coming out. I did hear of him just being, you know, in that kind of first-round, second-round discussion just throughout the Rams building and there was love for him there. But then having to play him … he is a good player. Sometimes I look at some of those corners and it doesn’t matter really how I feel. I want to know how [Rams QB Matthew Stafford] feels and I know how Stafford felt about him in terms of just a good young player. You can tell that he just understands ball. Like he understands the game,” LaFleur said.

LaFleur explained that Johnson’s ability to change things up made him difficult for an offense to read.

“When we came out here, he’s a good player, and you saw what [general manager Monti Ossenfort] and Arizona saw… You don’t know when he’s going to change up and throw a little curveball out there for you. I’m really impressed with him. Love the dude and I think he’s got a high ceiling,” LaFleur said.

The Rams got a good look at that challenge in Week 14 of the 2025 season. Los Angeles beat Arizona 45-17 on December 7, with Puka Nacua putting together seven catches for 167 yards and two touchdowns. One of those scores came on a 31-yard touchdown against Johnson late in the third quarter.

The play came immediately after an Arizona turnover, with the Rams facing first-and-10 at the Cardinals’ 31-yard line. Nacua lined up outside against Johnson and ran a hitch-and-go double move. Stafford stepped up under light pressure and threw a slightly underthrown pass down the left sideline. Nacua tracked it through contact, leaped over Johnson and backpedaled into the end zone.

Nacua later explained that Johnson’s earlier play had helped him decide how to run the route.

“Some of the double moves in the past, I’ve rushed them. But on this one, I wanted to sell it well, knowing that [Will] Johnson had driven back to the ball for a pass breakup prior to that… I have complete trust in No. 9 [Stafford]. Wherever he puts that ball, I’m like, I have no fear and no doubt that it’s a spot for me, so it always feels good when we connect on some of those ones,” Nacua said.

Johnson was the primary coverage defender on Nacua for five routes. Nacua was targeted four times in those situations, catching three passes for 69 yards and two touchdowns.

Johnson had already shown those instincts earlier in his rookie season. Against the Saints in Week 1, he recorded three pass breakups and earned the second-highest PFF coverage grade among NFL cornerbacks that week. He also had an interception wiped out by an illegal contact penalty.

Johnson finished his rookie season with 10 pass breakups in 12 games and 10 starts. Now, his second season has started with another concern. The Cardinals have listed his current issue only as a lower-body injury, while LaFleur has said he is “progressing well” in his rehabilitation. Arizona beat writers do not currently expect him to miss the season opener against the Los Angeles Chargers, although his practice participation will determine his final status.

LaFleur has also explained why Arizona has been careful about giving away more information.

“I’m going to be as transparent as I can, but at the same time, I think we know there’s a team over in California that’s listening to this too right now. Per the rules, we don’t need to say anything this week. Quite honestly, it’s going to be for every team. 48 hours is a huge deal in terms of some of these guys recovering, rehab, and all those kinds of things,” LaFleur said.

For LaFleur, Johnson’s biggest strength may be that an offense cannot always know what is coming.

“You can tell that he just understands ball. Like he understands the game… You don’t know when he’s going to change up and throw a little curveball out there for you,” LaFleur said.