Beckham is among the best receivers in the game, a do-it-all type with game-breaking ability. Marshall is a six-time Pro Bowler with tremendous size and strength. Apple is holding his own against both.
The maturation of Apple, last year's first-round pick, has been noticeable early in training camp. It was evident during a live drill Tuesday when he closed quickly and knocked a pass out of Beckham's hands. Apple didn't allow a completion in live drills.
"It's a game of confidence, and I think Eli is out there with some confidence right now," coach Ben McAdoo said. "He has a ways to go fundamentally, and he works hard at it each and every day. And you can see him taking what he learns in the film room over to the practice field, and he's competing against some pretty good players out there and he enjoys that, he likes it.
"His confidence is going up and he's a big, physical player and he's playing to that."
Apple put on some weight this offseason, entering camp at 202 pounds. He was 195 last year.
But Apple said this spring it hasn't affected his speed. In fact, he said the GPS monitors the Giants use indicate he's faster.
From what he has shown at camp so far this summer it's not hard to believe. Apple has battled admirably with Beckham and Marshall. He has lost some, but he has seemed to win more often than not.
His growth is noticeable. His teammates have seen a jump.
"Tremendously," safety Landon Collins said. "Just the way he brings his knowledge to the game now that he understands, and he sees it faster. He's two steps before the play goes and he's understanding. He's not having his hands up, and that's the best part. He's looking in and he's contributing."
Year 2 has started well for the Giants' starting cornerback.
"I think I'm a lot more comfortable with the defense, a lot more comfortable with the guys," Apple said last week. "Now it's just about, like I said, putting the work in and just going hard every day."
He did that Tuesday during the first padded practice of the year.
Other practice notables from Tuesday:
Quarterback Eli Manning completed 10 of 13 passes during live drills but went just 1-of-3 on passes to Marshall. Manning threw high and hard to Marshall on one slant pass in the red zone that would've been a touchdown. The combination is still a work in progress.
In the backup quarterback competition: Geno Smith completed 5 of 10 passes with one of the throws being dropped. Josh Johnson went 3-of-5 with a fumble but had two passes dropped. Neither quarterback has separated early in camp. Smith's accuracy remains suspect though as he returns from a torn ACL.
Wide receiver Darius Powe continues to make a strong impression early in camp. He led all Giants receivers with four catches on Tuesday. He's an under-the-radar player to watch throughout training camp. Powe's size (6-3, 220) makes him an intriguing option.
The Giants seemed to concentrate on the running game in shoulder pads for the first time this summer. That meant they utilized a fullback more than we've seen in quite a while. Rookie fullback Shane Smith had some nice blocks during live drills, squaring up well on defenders and moving them backward. It was an encouraging sight to see, especially with the offensive line looking much like last year with their inability to displace defenders in the run game.
Rookie wide receiver Kevin Snead had a really rough afternoon. He struggled badly catching punts during a special-teams drill. The collegiate sprinter is trying to make a mark as a wide receiver/kick returner.
Injury update: Defensive end Devin Taylor and running back Shane Vereen worked on the side with a trainer. McAdoo said they both were sore and were dealing with lower leg injuries. Wide receiver/kick returner Dwayne Harris also left practice early with a shoulder injury.