The rookie first-round pick agreed to a four-year contract on Monday. He's eager to compete for a starting spot on Philadelphia's defensive line when training camp opens next month.
"That's basically what football is all about, competing, and I'm always up for competition," Cox said in a conference call.
Cox was the last of Philadelphia's nine draft picks to sign. The Eagles traded up three spots to select the defensive tackle from Mississippi State at No. 12 overall.
"My mindset is going in and just doing what I'm coached to do, what (defensive line) coach (Jim) Washburn wants me to do, and that's play hard and be relentless," Cox said.
Cox made the All-SEC first team after finishing with 56 tackles and five sacks last year. He played three seasons at Mississippi State and had 114 tackles. He also blocked five kicks.
Cox attended all of the team's organized team activities and rookie camp. He missed the first two days of the mandatory minicamp last week because his cousin and close friend was killed in a car accident.
"Dealing with the death in my family was a really bad time for me, and I kind of struggled a little bit," Cox said. "To get the contract signed is just a blessing. Melvin is in a better place right now and he'll be watching down on me on Sundays and every day, even during practice, he'll be looking down on me. He would've wanted nothing but the best."
Cox never expected his contract negotiations to drag on. He certainly didn't want to hold out like Philadelphia's first-round pick last year, offensive lineman Danny Watkins.
"You don't want to miss a few days of training camp because if you miss three days, then you're three days behind and somebody else is ahead of you," he said. "With the new CBA, it makes a lot of stuff easy and helps us get this out the way. I know my agent did a great job of negotiating. I think he did a good job in getting it out of the way so I can play football."