TEMPE, Ariz. — Heading into NFL roster cutdowns, Arizona Cardinals’ Cassius Marsh thought he’d be starting for the Seattle Seahawks this coming weekend.

The outside linebacker had practiced as a starting defensive lineman and in April had signed with the Seahawks after the best season of his career, a 5.5-sack campaign for the San Francisco 49ers.

But then came the weekend’s NFL blockbuster: the Seahawks traded for pass-rusher Jadeveon Clowney, who forced his way out of Houston, making Marsh expendable from a roster and cap perspective.

“I really didn’t expect what happened,” Marsh said Monday, a day after signing with the Cardinals. “I don’t think too many people expected a trade like that.

“It was a little weird for me, but I’m a believer that everything happens for a reason.”

Cardinals head coach Kliff Kingsbury said the team was “thrilled” the pass-rusher was available.

Adding the soon-to-be-27-year-old behind Chandler Jones and Terrell Suggs not only gives Arizona a capable third outside linebacker, but insurance in the case one of the projected starters gets hurt. He’s coming off a 38-tackle campaign, is still relatively young and has 68 games of regular season experience.

“Very smart player, very physical, very tough,” Kingsbury said. “In our scheme, we see him being able to do multiple things. Excited to get him acclimated and caught up as soon as possible.”

Marsh, a first-round pick by Seattle in 2014, spent his first three years with the Seahawks and last two in San Francisco, with a one-year stint in New England sandwiched in between.

Joining Arizona checked a number of boxes.

The Cardinals went after him hard, making him feel wanted. With a five-and-a-half-month-old son, the UCLA product and California native wanted to stay close to home on the West Coast. There’s also now a little bit of motivation.

“I don’t care about those teams. All I care about is crushing them,” Marsh said of his former NFC West squads in Seattle and San Francisco.

“If I’m being 100% honest, there’s two teams in this conference that I really hate, and so there’s that,” he added.

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