The New York Giants are beginning the transition from training camp to the regular season, which is just two weeks away. They returned to the practice field on Sunday to prepare for Thursday's preseason finale and what lies beyond.

Here are five things we learned:

1. Daniel Jones will start preseason finale; Eli to sit. Coach Pat Shurmur, who usually likes to let any news about playing time "reveal itself" in the preseason, definitively said today that rookie Daniel Jones will start the fourth and final preseason game in New England. Eli Manning will not play in the finale, and has not done so since playing all five preseason games in 2014 after the Giants opened in the Hall of Fame Game. Manning heads into the regular season, which will begin with him under center on Sept. 8 in Dallas, after completing nine of 13 passes for 86 yards and a touchdown in three preseason games. The 16-year veteran played the first series of each game, and that was it. The three drives yielded a three-and-out, a touchdown and a field goal.

"He's done a lot of really good stuff out here," Shurmur said. "He's much more comfortable with what we want to do on offense this year than last year. I feel like as he gets the work he needs in practice, the game work he's gotten will help him be ready for the Cowboys."

2. DeAndre Baker (knee) returned to practice, needs to get sea legs back. With the regular-season opener two weeks away, cornerback DeAndre Baker took a step in the right direction. The rookie first-round draft choice returned to practice and rotated with the first team, which is where he had been before spraining his left knee on Aug. 11.

"I think for the most part he looked pretty good," Shurmur said. "He needs to get his sea legs back. We'll see how he responds here in the afternoon after being out there, and we'll see how much more we can give him tomorrow."

3. Sam Beal confident he will avoid IR for a second time. The Giants used their 2019 third-round pick a year early when they selected cornerback Sam Beal in the supplemental draft. Since then, injuries have limited his number of practices, let alone games. After spending all of last season on injured reserve with a shoulder injury, a hamstring has set him back this year. He made progress on Sunday by participating in individual drills for the first time.

"With soft tissue injuries, you don't want to rush back," Beal said. "You want to take your time. If you rush back, your chances of ruining it again [increase]. You don't want it to run into the regular season. I'd rather go down early than later. It is what it is."

Beal then vowed, "I'm not going back on IR."

4. Giants reacted to "warrior" Andrew Luck's retirement. Colts quarterback Andrew Luck, a four-time Pro Bowler, stunned the sports world last night by announcing his retirement. Luck, 29, cited the "injury-pain-rehab cycle" that he had been stuck in for the last few years as the primary reason.

"I was a little surprised like anybody," Shurmur said. "I've always enjoyed watching him play. He's a tough, competitive guy. For whatever reason, he feels like he just can't go anymore. That's a tough decision to make. I don't know him well enough to comment beyond that, but I wish him well."

Shurmur added: "This is a very physical game. Unfortunately, a lot of players have had a lot of major injuries, which kind of adds up on a person. Nobody knows their body better than the guy that's walking around in it. For whatever reason, he feels like he can't go anymore. I've always thought he played the game like a warrior. He's played at a high level and took a lot of hits. They've added up on him, and he's no longer playing."

Giants safety Michael Thomas has known the fellow Houston native since high school before they went on to be teammates at Stanford. Luck was the first overall pick in 2012 while Thomas went undrafted the same year. 

"That's my brother," Thomas said. "I grew up playing against him when we were in high school. I've known him since I was 14 years old. It's a personal issue, obviously. I'm not going to disclose what him and I talked about personally. But I support him. He had a great, great ride. If that's the decision he makes, it's probably for a good reason."

Luck's injuries also speak to the incredible ironman run by Manning.

"I think that's unique to Eli," Shurmur said. "I've been around a lot of quarterbacks that have had a few injuries, and some that had a lot, like Sam Bradford. Yeah, that's part of Eli's charm is that he can stay out there game after game. Being available and being able to play is huge."

5. There were many "coachable moments" after third preseason game. Shurmur, a former All-Big Ten center and co-captain at Michigan State, is an offensive lineman at heart. After Sunday's practice, he was asked about the play of Will Hernandez in the third preseason game in Cincinnati. The second-year left guard drew three penalties – a face mask (declined), false start and holding (declined) – while going up against seven-time Pro Bowl defensive tackle Geno Atkins. It was just the tip of the iceberg that night as the rest of the team had some untimely drops and a lost fumble.

"I think when I look at the Bengals game, we made enough plays to win the game in total," said Shurmur, whose team improved to 3-0 in the preseason. "But there were many coachable moments for all of the players that competed in that game."

For the first time, one of those players was Darius Slayton. The rookie wide receiver made his NFL debut after dealing with a hamstring injury. He had one catch for 27 yards, which set up a one-yard touchdown run by Rod Smith in the second quarter.

"He did a good job," Shurmur said of Slayton. "It was a good first step. Again, he's another young player (like Beal) that would have benefited with all of the work he would have gotten up until that point. But it was a good first step."