Brian Baldinger got a pretty good feel for Darius Slay’s competitiveness four years ago when the NFL Network analyst traveled to the Pittsburgh Steelers’ training camp in Latrobe to watch two days of joint practices between the Steelers and Slay’s Detroit Lions.

“All he wanted to do was go against Antonio Brown every drill," Baldinger said. “Now, Antonio beat him. But every time he lined up in any one-on-one, Darius made sure to line up against him.

“He just wanted to go up against the best every day. I thought that was pretty telling about what kind of a player and what kind of a person he is."

Slay was acquired by the Eagles Thursday in exchange for third- and fifth-round picks in next month’s draft. The trade came two days after the Eagles were outbid by the Miami Dolphins for Byron Jones, who was the top-rated cornerback on the free-agent market.

“Slay is everything you want in a corner," Baldinger said. “He’s smart. He’s competitive. He’s country as the day is long. He has a smile on his face every day. He’s a great culture guy."

Lions coach Matt Patricia might beg to differ. While Detroit’s willingness to trade away a three-time Pro Bowler who led the league in interceptions just three years ago has been spun by many as a contract situation, there was a little more to it than that.

Patricia just didn’t care for Slay, sources said. He wasn’t his type of culture guy.

When Slay posted a picture of himself on Instagram exchanging jerseys with a Green Bay Packers player minutes after a heartbreaking one-point loss to the Packers in Week 6, Patricia was hacked.

“He’s a good guy," a member of the Lions organization said of Slay. “He just wasn’t their kind of guy. [Defensive end] Tre Flowers was inconsolable after that loss. That’s how Patricia expects players to react to a loss like that. Not by exchanging jerseys and posting a picture of it on social media."

Whether trading for Slay was a better move than giving crazy money to Jones is a question that only time can answer.

The money they saved by not overpaying Jones and negotiating a three-year, $50 million team-friendly contract extension with Slay allowed them to also add free agent defensive tackle Javon Hargrave. That probably wouldn’t have happened if they had corralled Jones, whose five-year, $82.5 million deal with the Dolphins includes $57 million in guaranteed money.

Slay’s extension, which includes $30 million in guarantees, doesn’t kick in until next season. He’ll make $10 million in 2020 on the final year of his previous contract.

Slay has 104 pass defenses in seven NFL seasons, which is the most in the league over that time. But he is 29 and not coming off one of his better seasons.

With Slay slowed by a hamstring injury a good chunk of the season, opposing quarterbacks completed 58.3% of their passes thrown in his direction, which was the highest percentage against him since 2016. He gave up 14.1 yards per catch, the highest average since his rookie year.

Pro Football Focus rated him as just the 53rd best corner in the league last season, down from 20th in 2018 and 14th in 2017. It ranked Jones 10th last season.

“Byron probably is a better all-around athlete when you look at his [44 ½-inch] vertical [jump] and his ability to change direction," Baldinger said. “He’s an elite player. Might be fundamentally a little bit more sound than Slay.

“But you can’t argue with the way Darius Slay plays the game. He plays the game the right way. And he’s going to get you some interceptions. Byron just isn’t going to do that."

Jones has just two career interceptions in four NFL seasons.

There were some extenuating circumstances to Slay’s play last season. The hamstring injury was one. The Lions’ pass rush was another. It was awful.

The Lions had the third fewest sacks in the league (28) despite the fact that they were thrown on the second most times (611). That put a lot of pressure on the secondary, particularly Slay, who usually was matched up with the opponent’s top wideout.

Slay still had some very good games. In a 13-10 Week 2 win over the Los Angeles Chargers, Slay followed Keenan Allen the whole game.

Allen, who caught 104 passes last season, was targeted 15 times by Philip Rivers in that game and caught eight passes for 98 yards. But Slay didn’t give up a touchdown and picked off a Rivers pass for Allen in the end zone with a minute left in the game to clinch the victory.

“It was just a great example of how competitive he is and what you have to do in this business when you get beat by a great player like Allen," Baldinger said. “You’ve gotta line back up and have amnesia and play the next play. And that’s what he does. The Eagles are getting a cornerback they can count on."

Eagles defensive coordinator Jim Schwartz, who coached Slay as a rookie in 2013 in his final year as the Lions’ head coach, rarely has assigned a cornerback to the other team’s top wide receiver. Ronald Darby did it a couple of times, but that’s been about it. For the most part, Schwartz had his corners play sides. That could change with Slay’s arrival.

“He hasn’t had a corner who could really do it," Baldinger said. “But if you’re playing, say, [the Cowboys’] Amari Cooper, it probably would be a good idea to put somebody on him that can handle his route-running ability.

“I’m not saying Slay can shut you down the way [the Patriots’] Stephon Gilmore can shut you down. But he’s capable of doing it."

Slay is a naturally upbeat person. Baldinger spent a couple of hours with him at the Pro Bowl in Orlando in January doing a film session with him for NFL Game Pass and came away impressed.

“I don’t think he has any bad days," the NFL Network analyst said. “He’s always smiling. He’s very personable. He just lights up a room when he walks into it.

“You’re not going to see the trash-talking and finger-pointing from him that you see from other players. That’s not him. He has a healthy respect for the people he plays with and against. He does it the right way. He’s not going to get overly emotional and do anything to harm his team."