"I wanted to stay for a minute, but I knew how me and Matt Patricia were, and that wasn't going to last long," Slay said during a Thursday interview with WJR radio in Detroit (h/t Justin Rogers of the Detroit News).
According to Rogers, Slay added that "he didn't respect Matt Patricia as a person" before the trade and knew their relationship was destroyed after the first year, though their second season together in 2019 was smoother.
While Patricia was a successful defensive coordinator for the New England Patriots and helped the team win two Super Bowls from 2012-17, he is a mere 9-22-1 in two years as the head coach for the Lions.
It is hard to blame Slay for the poor record.
The 2013 second-round pick has made the Pro Bowl in each of the last three years and routinely matched up against the opponent's No. 1 receiver. He also led the league with eight interceptions and 26 passes defended during his All-Pro effort in 2017.
Despite his impressive play, Slay said during Thursday's interview that Patricia told him he is good and not elite like Richard Sherman and Aqib Talib, and he didn't deserve to work out with those difference-makers.
He addressed that sentiment further during while speaking with Michael Rothstein of ESPN.com:
"I'm like, 'Huh?' I said, 'Huh.' I'm trying to see where he's coming at. He said I wasn't an elite corner and that I'm not in they category. I was coming off an All-Pro year, eight picks. That told me right there that he didn't have no respect for me. He told me I was a good player but then to tell me what I'm not, so I said, OK, I just took that to the chin and said, 'OK, that's cool.'
"Then I bounced back to two back-to-back Pro Bowlers on him. Let him know how elite I was."
Patricia may not have fully believed in him, but Philadelphia does.
Schefter reported the Eagles agreed to a three-year, $50 million contract extension that made him the league's highest-paid cornerback. Slay has some familiarly with the coaching staff. Eagles defensive coordinator Jim Schwartz was Detroit's head coach during Slay's rookie season.
"It was good, even though it was a short period of time. It was only one year, but one thing about Schwartz, he was a genius, real smart guy, man," Slay said of his relationship with his new DC, per John Clark of NBC Sports Philadelphia. "Knows the ins and outs of the defense, and I know he's got those guys flying around."
It sounds like Slay is much more excited about playing for Schwartz than he was for Patricia.