Anthony Lynn had a giant smile on his face during practice for the AFC team at the Pro Bowl. It was a look of excitement and relief all in one. The Chargers coach knew he had nothing to worry about.

For this week, Lynn had no fear.

Maybe it's because he was only coaching an exhibition game with nothing on the line. But it's also easier to stay calm when your biggest adversary, who happens to be the NFL MVP, is also on your side.

Instead of trying to stop Chiefs quarterback Patrick Mahomes, Lynn got the chance to coach him. As Lynn said, this is "a lot more fun." It was hard for Lynn to contain his smile.

"He's going to be good for a long time," Lynn said. "It's hard because he can do so many things. He can move around, create, gets the ball out quick. He can throw it any way imaginable."

In 2018, Mahomes was a star in Fantasy and reality. But now he has to repeat that performance — if he can.

History tells us there's regression coming from his enormous stats last year. But at 23, with Andy Reid and standout weapons on his side, Mahomes has the chance to be special again this season. He's worth drafting as the No. 1 quarterback in all leagues. It's just a matter of when you select him on Draft Day.

Before we address Mahomes' Fantasy value for 2019, we should marvel at his performance last year. It was just his second season in the NFL, his first as a starter, and he shattered expectations.

Taking over for Alex Smith, who was more than just the game manager he was labeled as for many years in Kansas City, Mahomes helped the Chiefs dominate on offense. He led them to the AFC Championship Game, where they suffered a tough 37-31 overtime loss to the Patriots. Mahomes never touched the ball in overtime because New England scored on its first possession. But many pundits believe Kansas City could have rallied and eventually won because of Mahomes if the overtime rules were different.

His stats in 2018 were ridiculous with 5,097 passing yards, 50 touchdowns and 12 interceptions on 66 percent completions. He also added 272 rushing yards and two touchdowns, joining rare company with that kind of production.

There have only been 11 times where a quarterback passed for at least 5,000 yards, and it's happened from just seven guys in NFL history. Drew Brees has passed for at least 5,000 yards five times, while Peyton Manning, Tom Brady, Ben Roethlisberger, Mahomes, Dan Marino and Matthew Stafford have each done it once.

And only three quarterbacks in NFL history have passed for at least 50 touchdowns, with Manning and Brady the other two. Manning in 2013 and Mahomes are the only two quarterbacks with 5,000 passing yards and 50 touchdowns in the same season.

For many, including members of the Chiefs, no one expected this kind of production from Mahomes. Star tight end Travis Kelce said he "cringed" when the team got rid of Smith in a trade to Washington.

But Kelce quickly realized just how good Mahomes could be, and he understood the move to go with the kid. 

"It's hard to really explain because it was a whole different type of energy," Kelce said. "I try to explain it that when Alex had the keys to the car, you're riding to a good tune. It's fun. It's a good time. Your favorite song comes on, you're like, 'Yeah, I like that song.' You're enjoying it. He had a hell of a season (in 2017).

"And then Patrick comes in, and it's a new song that you haven't heard before, but you freaking love it. You're blasting it. You just keep listening to it over and over and over again. You're like, 'Who wrote this again?' You're trying to get acclimated to it, and it was just a fun atmosphere. It was a fun ride."

That fun ride took some getting used to for Kelce, especially with how unique Mahomes is as a passer. He has a rocket arm, but he's also not afraid to be creative with the ball.

He's thrown the ball left-handed in games, attempted no-look passes and has changed his arm angle many times to complete a pass. That took some getting used to for Kelce.

"With Pat, you don't know what you're going to get," Kelce said. "You're going to get maybe a sidearm, underarm, a left-handed throw. It might not always be a tight spiral. It might be like a screwball that's going away from you a little bit. A knuckleball that you're trying to gauge it. It keeps you on your toes. But at the same time, the more you get acclimated to that, the more your focus changes to see it all the way into your hands. It's definitely a non-stop, conscious effort to stay focused on the ball and know that he's a quarterback that's going to get the ball to where it needs to be."

Mahomes' style of play made it difficult on opposing defenses, and he scored at least 21 Fantasy points in all but one game last season in leagues where you get six points for passing touchdowns. That one-game letdown was in Week 5 against Jacksonville when he was held to 15 Fantasy points.

Jaguars Pro Bowl defensive end Calais Campbell said getting pressure on Mahomes is key, although he was sacked just 26 times in 2018. Still, like most quarterbacks, if you make them uncomfortable in the pocket then they don't perform as well. Mahomes, according to several defenders, is no different.

"You just have to get to him," said Campbell, who helped limit Mahomes to 313 passing yards, no touchdowns and two interceptions, although he did have a rushing touchdown. "Get to him early and often. And you can't miss him when you get there."

Added Denver Pro Bowl cornerback Chris Harris: "You have to keep him in the pocket and force him to throw there all day. Don't let him scramble and beat you outside of that pocket. That's when he really makes those big gains on you."

The Broncos played well vs. Mahomes in one of the two games against him, which was Week 4 in Denver. He passed for 304 yards and one touchdown, though he also scored on the ground in that one. He scored 24 Fantasy points in that game, but he had to earn it.

In the second meeting against Denver in Week 8 at home, Mahomes had a much better outing with 303 passing yards, four touchdowns and one interception for 34 Fantasy points. It was one of 10 times he scored at least 30 Fantasy points in 2018.

Harris said you could see Mahomes improve as the season went on, which is the sign of greatness. As Harris said, Mahomes was able to adjust to what defenses were showing him.

"He can make every throw," Harris said. "When you have a guy that can make all the throws from every angle, on the run or in the pocket, it makes him more dangerous. He was the best player we faced this year. You see how he played us. He made a lot of things happen just off the script. That's why I think he's one of the best."

Rams Pro Bowl safety Eric Weddle played in Baltimore last season, and he faced Mahomes in Week 14. The Ravens frustrated Mahomes for most of the game before he led a late touchdown drive in the fourth quarter to force overtime, and the Chiefs won 27-24.

Mahomes had a career-high 53 attempts in that outing, completing 35, and he finished with 377 passing yards, two touchdowns and one interception for 25 Fantasy points. Weddle said the Ravens had a great game plan against Mahomes, but they didn't finish the job.

"We did a great job against them up until the last series of the game," Weddle said. "We held him in check up until then. A guy like that in that offense, you have to be perfect. ... He's the future. He's a talented, great kid. He's only going to get better and better, which is scary for the league."

But how will Mahomes get better in 2019? History tells us that 5,000-yard passers and quarterbacks who throw for 50 touchdowns tend to struggle the following year.

Of the 11 times a quarterback has passed for at least 5,000 yards, two played last season with Mahomes and Roethlisberger (5,129 yards). But of the previous nine times a quarterback passed for 5,000 yards, the average decline in yards for the following season was 474 — and every one of them got worse. Brees is the only quarterback in NFL history to pass for at least 5,000 yards in consecutive seasons when he reached the mark for three years in a row (2011-13).

And of the two other quarterbacks with at least 50 touchdowns, Manning went from 55 touchdowns in 2013 to 39 in 2014. And Brady went from 50 touchdowns in 2007 to 28 touchdowns in 2009 (he tore his ACL in Week 1 in 2008).

So where does that leave Mahomes? Will he play like Brees and continue to stockpile 5,000-yard seasons on top of each other? Or is 2018 just a flash in the pan?

Reid isn't worried about Mahomes having a letdown in 2019. 

"Defenses will have an opportunity to study him, and there are a lot of great minds, a lot of great defensive coordinators in the league," Reid said. "They'll present certain things to him that they think will be effective against this offense, and then he'll have to answer those. But for now, we're going to add things in, and he's going digest that. He's going to go back and look at all the things we did our studies on. These cut ups will be invaluable for him on the different plays that he's run this past year, study those and see where he can get better in those areas.

"And I think it's a great growing period from Year 1 to Year 2, and he'll handle it the right way. A lot of guys don't. They get complacent. He won't do that."

Mahomes benefits that star receiver Tyreek Hill isn't going to face a suspension, which was a potential concern for his Fantasy value this offseason. Along with Kelce, Sammy Watkins and Damien Williams, who is a good pass-catching running back, Mahomes is surrounded by talented weapons.

And then there's Reid, who has been phenomenal for Fantasy managers with the quarterbacks he's coached. From Donovan McNabb to Michael Vick to Smith, Reid has been a quarterback guru. But Mahomes might be the best quarterback Reid has ever had.

Reid said Mahomes proved himself last season and should do well again this year.

"You really don't know until you're there and the bullets are flying," Reid said. "Most games are determined by seven points or less, so you're sitting there going, 'How is this guy going to handle it?' He just grits down, and it's a beautiful thing to watch. Until that last play is over, he's going to try to rip your heart out and score — and bring everybody with him. He's not a self-promoter. He wants everybody to pick their game up with him."

Fantasy players should love Mahomes. But just don't overvalue him on Draft Day. His Average Draft Position in early August is Round 1 at No. 11 overall, which is too soon in one-quarterback leagues. Quarterback is a deep position, and you can get a great passer at a better value, even if Mahomes is fantastic once again this year. 

Just understand that his stats might decline, which is what history tells us. And you don't want to be chasing stats from the previous year when building your Fantasy team.

That being said, opposing defenses and coaches, like Lynn, should fear him. When he's on his game, no one on the opposing sideline is smiling.