Atlanta Falcons safety J.J. Wilcox has suffered a season-ending ACL injury, coach Dan Quinn confirmed Tuesday.

Wilcox suffered the injury on the first day of training camp Monday and had been scheduled to get a second opinion.

The 28-year-old veteran remained on the ground kneeling on his left knee after a play and didn't immediately get up when defensive backs Isaiah Oliver and Damontae Kazee came over to check on him. Both Kazee and strong safety Keanu Neal helped Wilcox off the field a little more than an hour into practice.

Wilcox was an important offseason signing as the Falcons searched for quality depth behind Neal and starting free safety Ricardo Allen. Neal had a season-ending ACL tear in 2018, and Allen had a season-ending Achilles' tear. Both practiced in 11-on-11 drills Monday, but their team reps were limited.

Wilcox impressed coaches during the offseason with his ability to play both safety spots. The Falcons even showed a package Monday with Neal, Allen and Wilcox all on the field together.

Without Wilcox, the Falcons might turn to Chris Cooper and Sharrod Neasman to provide depth at the position. There's always the possibility of signing another free-agent safety, and Kazee, who is playing nickel corner now, thrived as Allen's replacement at free safety last season.

ESPN's Vaughn McClure contributed to this report.