The Cleveland Browns were the media darlings going into the 2019 NFL campaign. They were considered AFC North favorites, and many had them pegged as a legitimate Super Bowl contender.

But they have looked anything but the sort over the first five weeks.

The Browns have gotten off to a 2-3 start, most recently suffering a blowout loss at the hands of the San Francisco 49ers on Monday night.

It's blatantly obvious that Cleveland has a litany of problems, and even though there is still time for the Browns to turn things around, it is, in fact, time to panic if you're a Cleveland fan.

Here are three reasons why:

3. The Browns Can't Stop the Run

The Browns were punctured for 275 rushing yards by the 49ers on Monday night, the latest example of them getting absolutely shredded by an opponent's ground game.

The Titans did it to them in Week 1, and even though Cleveland beat the Ravens last week, Baltimore still took it to the Browns via the ground attack.

Overall, Cleveland ranks 29th in the NFL in defending the run, which is a big reason why the Browns rank 18th in total defense and 21st in points allowed.

Cleveland tried to improve its defense this offseason, bringing in names such as Olivier Vernon and Sheldon Richardson and drafting Greedy Williams, but that has not helped the Browns in guarding against the run.

2. The Schedule

Cleveland has had a brutal schedule over the first five weeks of the season, and it is not about to get any easier.

The Browns will host the 4-1 Seattle Seahawks next Sunday before heading into their bye week. They will then have to head on the road to battle the New England Patriots.

So, there is a distinct possibility that Cleveland is 2-5 heading into its Week 9 matchup against the Denver Broncos.

Now, the Browns' schedule does ease up a bit after that, but at that point, it might not matter, as it is going to be very, very tough for Cleveland to climb out of a potential 2-5 hole.

1. Baker Mayfield Is Having a Sophomore Slump

After an incredible rookie campaign in which he set the single-season rookie record with 27 touchdown passes, Baker Mayfield has taken a massive step back in Year 2.

Through five games, Mayfield has thrown for 1,247 yards, four touchdowns and eight interceptions while completing just 55.9 percent of his passes and posting a passer rating of 68.5.

We can blame first-year head coach Freddie Kitchens all we want, but the fact of the matter is that Mayfield is not playing well, and he has yet to really have a great game this season.

I'm not sure if defenses have learned him or if something else is going on, but whatever it is, Mayfield needs to adjust, because a legitimate argument can be made that he has been the worst starting quarterback in football thus far this season.

It's not like Mayfield has a lack of weapons, either. He has Odell Beckham Jr. and Jarvis Landry, not to mention Rashard Higgins and now Antonio Callaway. Yes, David Njoku is hurt, but between Nick Chubb and the receivers, Mayfield has more than enough options to be just fine.

But he has been terrible. There is no way around it.