"Really everything," Garrett said Tuesday from the NFL owners meetings in Orlando. "At the quarterback position -- and maybe every position, but maybe most glaringly there -- there's so much to learn over the course of your career. That's why the guys at that position play longer and it seems like they're playing their best football well into their 30s."
Prescott doesn't turn 25 until July 29. He has a 22-11 record, including playoffs, in his first two years with the Cowboys. After a record-setting rookie season when he threw 23 touchdown passes and was intercepted just four times, Prescott had 22 touchdown passes and 13 interceptions in 2017 with the Cowboys finishing 9-7.
"He's done a lot of good things, but he knows, we know, everybody knows he's got to get better," Garrett said. "One of the exciting things about him is he has such a determination to get better every day. He has a great spirit. He loves the game. He's going to work very hard at it. I think he has to work on the physical part. The fundamentals have to continue to be refined. And that's everybody. That's footwork, delivery, getting away from center, his mechanics in the gun, getting the ball out quicker, being more accurate. All the things that every quarterback in this league is working on, he has to continue to refine those.
"His understanding of what defenses are trying to do to us, how the offense overlays on the defense, he'll continue to get better at that. But this guy is a natural leader. He's had a lot of success right away. He has a great hunger to get better. And he's certainly going to do that."
Garrett said the top area where the Cowboys have to improve is the passing game. They ranked 26th in the NFL last season after ranking 23rd in 2016 and 27th in 2015. Though the ranking was low in 2016, Prescott's efficiency, coupled with a strong running game allowed the Cowboys to score 418 points. In 2015, the Cowboys saw Tony Romo start and finish two games because of collarbone injuries.
From 2007 to '14, the Cowboys had a passing game rank at least in the top half of the league, finishing in the top 10 six times.
The biggest help to Prescott in 2018 would be a full season of Ezekiel Elliott. He missed six games in 2017 because of a suspension, altering the look of the offense. Cole Beasley recently told the Dallas Morning News, the Cowboys asked Prescott, "to be Superman and relied on him so much."
"Obviously, what you're trying to do is attack different ways and spread the burden for every player around," Garrett said. "That's why we talk about being a balanced offense, so no one feels like they have to do it all. And so the better your team is, the more balanced you can be. When I say balanced, it's offense, defense, special teams. You want to have balance throughout your units and then within those units, you don't want any one guy to have to carry the burden. And the better your team becomes, the more you can spread that out. And certainly we try to do that with every team we build."
To aid Prescott, the Cowboys have added wide receivers Allen Hurns and Deonte Thompson in free agency. They also signed Cameron Fleming, who could play right tackle and move La'el Collins back to left guard.
"Obviously a couple years ago in his rookie year, we won 13 games and he was a big part of that. I thought we did a good job of attacking defenses a lot of different ways," Garrett said. "Certainly we were predominately a running team, but he was very effective throwing the football. And in games where we had a lot of play action, movement, all of those things, he was certainly very effective. But when we played some games in the last couple of years where he had to bring our team back late in the game and do it again where we're throwing the football and we're in two-minute mode and he's been really, really good at that up to this point. Now, does he have to get better at everything? Absolutely. And we're working very hard with him on that. We're excited to get back with him in the middle of April and get back to work."