On January 4, 2016, Apple announced his decision to forgo his remaining eligibility and enter the 2016 NFL Draft. Apple attended the NFL Scouting Combine and completed the majority of combine drills before suffering cramps. He finished with the tenth fastest time in the 40-yard dash among all participating players at the NFL Combine.
On March 11, 2016, Apple attended Ohio State’s pro day, but opted to stand on his combine numbers and only performed the short shuttle, three-cone drill, and positional drills. Apple had pre-draft visits with multiple teams, including the Buffalo Bills, San Francisco 49ers, and Tennessee Titans. At the conclusion of the pre-draft process, Apple was projected to be an early to mid first round pick by NFL draft experts and scouts. He was ranked the third best cornerback prospect in the draft by DraftScout.com, was ranked the fourth best cornerback by NFL analyst Mike Mayock, and was ranked the sixth best defensive back by Sports Illustrated.
The New York Giants selected Apple in the first round (10th overall) of the 2016 NFL Draft. Apple was the second cornerback drafted in 2016, after Jalen Ramsey (5th overall). It was reported that the New York Giants had initially planned to draft linebacker Leonard Floyd or offensive tackle Jack Conklin. However, circumstances changed after Laremy Tunsil unexpectedly fell out of the top ten. The Tennessee Titans traded ahead of the Giants to draft Jack Conklin (8th overall) and the Chicago Bears traded ahead of the Giants to select Leonard Floyd (9th overall). New York Giants’ General Manager Jerry Reese opted to keep the tenth overall pick and selected Apple who was their highest graded player available on their draft board without any issues or injuries. Draft analysts and fans criticized the selection of Apple as many deemed it to be a reach.
On May 6, 2016, the New York Giants signed Apple to a fully guaranteed four year, $15.15 million that includes a signing bonus of $9.21 million.
He made his professional regular season debut in the New York Giants’ season-opener at the Dallas Cowboys and recorded four solo tackles during their 20–19 victory. On September 25, 2016, Apple earned his first career start and recorded one solo tackle in a 29–27 loss to the Washington Redskins, but left the game in the second quarter after suffering hamstring injury. Apple was inactive for the Giants’ Week 4 loss at the Minnesota Vikings with a hamstring injury. He was also sidelined for their Week 6 win against the Baltimore Ravens due to a groin injury. On November 7, 2016, he started his second game in a row and made four solo tackles against the Philadelphia Eagles but was benched in favor of Trevin Wade as the Giants won 28–23. On November 14, 2016, Apple started his first game at outside corner, with Rodgers-Cromartie covering the slot and made one solo tackle in a 21–20 victory over the Cincinnati Bengals. In Week 11, Apple collected a season-high nine combined tackles in a 22–16 victory over the Chicago Bears. On December 4, 2016, Apple recorded five combined tackles, broke up two passes, recovered a fumble, and made his first career interception in the Giants’ 24–14 loss at the Pittsburgh Steelers in Week 13. Apple intercepted a pass attempt by Steelers’ quarterback Ben Roethlisberger, that was originally intended for wide receiver Eli Rogers, during the third quarter. Apple started the last ten games of the season and finished his rookie season in 2016 with 51 combined tackles (41 solo), seven pass deflections, one interception, and a forced fumble in 14 games and 11 starts.