The Cleveland Browns have had one of the busier offseasons in recent memory, adding pieces such as Odell Beckham Jr., Kareem Hunt, Sheldon Richardson and Olivier Vernon and stamping themselves among potential Super Bowl contenders as a result.

Still, the Browns obviously have a long way to go.

As star-studded as Cleveland's roster looks, the fact of the matter is we don't know if it is going to translate into on-field results, and this is a franchise that has not made the playoffs since the 2002-03 campaign.

While the Browns certainly have potential, there are some reasons to doubt them.

Here are the three main areas of concern for Cleveland going into 2019:

3. Defense

I think we tend to forget that the Browns ranked 30th in the NFL in defense in 2018. Yes, Cleveland added pieces like Richardson and Vernon, but neither player is a star, and the Browns have a whole lot of question marks on that side of the ball.

For starters, Cleveland's linebacking corps is incredibly inexperienced and unproven, and it's not like the Browns have one veteran there to keep everyone in check. They have a whole bunch of young pieces who haven't accomplished much of anything yet.

There are also some concerns about the secondary. Denzel Ward looks like he could be special and the change of scenery from Green Bay did seem to Damarious Randall well this past season, but Morgan Burnett is a bit scary as a starter at this stage, and we really don't know what to expect from Terrance Mitchell and Greedy Williams.

2. Experience

The Browns had a really impressive second half this past year, but there were also no expectations on them whatsoever. People expected them to stink. Now, the Browns have a target on their backs. How are they going to respond to that?

Things always change when expectations arrive, so it will be interesting to see how Baker Mayfield and this young and inexperienced Cleveland squad handles that. It's not like it's just the roster that is young, either. Freddie Kitchens is going into his first season as an NFL head coach, and we have already heard of the Browns having some issues with offensive coordinator Todd Monken.

When the chips are down, is this Cleveland club going to be able to live up to the challenge? Or is it going to fold under the pressure?

Quarterbacks also typically don't take a big jump between Year 1 and Year 2, so it's entirely possible that Mayfield doesn't improve all that much even with all of his newfound weapons.

1. Entirely New System

It's not like the Browns were a playoff team that simply added a couple of pieces. This is a seven-win ballclub that basically revamped its entire team, and we have no idea how those pieces are going to fit.

At the moment, Cleveland is merely a collection of talent with potential. That's it. We have seen nothing from the Browns to think anything otherwise. And remember: the head coach that led them to a 5-2 second half this past season in Gregg Williams is gone.

New players, new system, new expectations, new everything.

We have already seen some dissension in the ranks between Mayfield and Duke Johnson, and Hunt is not even back from his suspension yet.

Sure, everything can mold nicely and the Browns could end up winning 11 games, but things could also blow up in John Dorsey's face. That locker room has some volatile personalities, after all.

Let's not act like Cleveland is a sure thing.