THOUSAND OAKS, Calif. -- When the Houston Texans traded star wide receiver DeAndre Hopkins to the Arizona Cardinals over the offseason, two thoughts crossed Los Angeles Rams cornerback Jalen Ramsey's mind.
"I felt bad for Deshaun Watson," Ramsey said. "And I just -- mentally had to get my mind right again."
Hopkins and Ramsey have a competitive history.
The two went head-to-head seven times when they played in the AFC South, but the matchup ended when the Jacksonville Jaguars traded Ramsey to L.A. in October last season.
A familiar foe, Ramsey says he and Hopkins are "cool" off the field but is quick to add, while chuckling, "On Sunday, we won't be."
With Hopkins now starring in the NFC West, Sunday is when Ramsey and Hopkins' twice-a-season rivalry renews as the Rams (7-4) visit the Cardinals (6-5) at State Farm Stadium (4:05 p.m. ET, Fox).
"Me being traded last year, got out of the division and didn't think I was going to be playing him again for a while," said Ramsey, smiling. "And just seems like he followed me. Wherever I'm going, he's going. I follow him during the games, he followed me to the division."
A three-time All Pro, Hopkins has three receiving touchdowns when the All-Pro Ramsey was the nearest defender. However, Ramsey has limited his separation from Hopkins to an average of 1.6 yards, according to NFL Next Gen Stats data.
"I'm looking forward to going against him," Hopkins told reporters. "He's a great football player."
With Ramsey nearest to him, Hopkins has caught 30 of the 64 passes he was targeted on.
"We've had some good battles," Ramsey said. "I've won some, he's won some."
Ramsey says no particular play or game against Hopkins stands out. However, the matchup has featured an outstretched, one-handed reception by Hopkins, multiple lockdowns from Ramsey, and plenty of physical hand-to-hand scuffling in between.
In first-year Rams coordinator Brandon Staley's defense, which ranks No. 2 in efficiency, Ramsey has served as lockdown cornerback, but also has been relied on to play other spots in the secondary, including inside.
Ramsey has 31 tackles, an interception and three pass deflections.
In a 23-16 victory over the Seattle Seahawks in Week 10, Ramsey shut down wide receiver DK Metcalf, the NFL's leading receiver with 1,039 yards, limiting him to two catches for 28 yards.
Then in Week 11, Ramsey battled wide receiver Mike Evans in a 27-24 win over the Tampa Bay Buccaneers. Evans finished with five catches for 49 yards and a touchdown -- though the score occurred when Ramsey was not defending him.
Now Ramsey must slow Hopkins, who has caught 77 passes for 967 yards and four touchdowns in his first season with Cardinals quarterback Kyler Murray.
"He's a guy that Kyler needs a play, he feels confident in finding DeAndre," Cardinals coach Kliff Kingsbury said. "And DeAndre is a guy who, for their limited time on task, has really fit in well with Kyler."
Staley says Ramsey has a great sense of what to expect from Hopkins on Sunday.
"He's a really dangerous player," Staley said about Hopkins. "He can really challenge you in the deep part of the field. He's physical. He can run the route tree inside and out. He's really good after the catch, if he catches it short, he can break tackles. It's going to be a fun matchup."
Ramsey says his approach to defending Hopkins evolved over 3½ years facing each other, but declined to elaborate. Some of those tactics are likely to be utilized Sunday.
"We both have grown and developed our skill set each time," Ramsey said. "You kind of get a hang of some things and you catch onto some things, that's probably what he's done, it's what I've done as well."
Early in their preparation for the Cardinals, safety John Johnson III said Ramsey had not shared many insights about Hopkins' tendencies. But Johnson added that there really was no need.
"That's going to be his duty," Johnson said. "I think we all know that."
A week after the Texans traded Hopkins to the Cardinals, Ramsey dropped a new hype reel on his Instagram feed.
The 44-second clip included sound bites from both players: "He's my favorite corner to go against," Hopkins said. "He's got a 99 overall rating in Madden. He's pretty much like that in real life, too," Ramsey said. The reel also included plenty of highlights of Ramsey and Hopkins battling.
"Respect is mutual but we gotta get after it," Ramsey wrote in a caption that accompanied the reel.
The video ended with three words written on screen: "The rivalry continues."