Demetrious “Mighty Mouse” Johnson has almost cleaned out the flyweight division. He has turned the 125-pound weight class into a barren wasteland, where there is hardly a sign of contenders who haven’t lost to the champion.

The key word there is “almost.”

Despite dispatching the top five fighters in the UFC flyweight rankings, Johnson still has challenges ahead in his own division before rendering the division devoid of fresh challengers.

Now, this isn’t to say that Johnson has major potential to lose to the fighters named below. The champion has honed his skills and become better with every fight—a scary thought for anybody willing to step up to face him. These are simply the fighters with the best chance to take down the champion.

John Lineker

Before losing to Ali Bagautinov at UFC 169 by unanimous decision, John Lineker was considered to be one of the next challengers to get a crack at Johnson. Bagautinov was supposed to be a stepping stone in that direction. First, though, Lineker needed to put to rest the questions of whether he could make the weight for his fights. Lineker didn’t do that. Then, he needed to beat Bagautinov. He didn’t do that either.

Lineker has missed weight three times in the UFC, including missing on the first attempt against Bagautinov. Lineker needs to figure things out on the scale, and then put together a couple of wins before getting a shot at the champion. One call to Mike Dolce is all Lineker needs.

With a chance to be a fresh face for Johnson, Lineker could spring to the front of the line. Furthermore, a fight with Johnson could lead to a sequel of Lineker’s “Fight of the Night” brawl with Louis Gaudinot. Johnson doesn’t brawl, but his striking certainly is entertaining to watch. His fast-paced stand-up arsenal against the power right hand of Lineker could make for a wildly entertaining fight.

Lineker also has some great ground-and-pound, plus a left hook that could sweep Johnson off his feet.

Zach Makovsky

There are two more potential fighters who could pose a problem for the champion: Zach Makovsky and Jussier “Formiga” da Silva. Unfortunately for them, they face each other at UFC 176. The battle between the two will most likely result in the next flyweight title challenger.

Makovsky is the former Bellator bantamweight champion. He lost his belt to Eduardo Dantas in his first defense in 2012. Makovsky stepped in to face Scott Jorgensen this past December inside the UFC’s Octagon and made it known to the rest of the flyweight division that he had arrived and is ready to make a run at the title.

Makovsky showed how wildly athletic he was in dispatching Jorgensen. He moved very well in that fight, and he’ll need that athleticism in order to keep up with the speedy movement of Johnson, who possesses a strong wrestling base and great grappling ability.

Makovsky is a dangerous fighter for anybody. If he is able to work on becoming more well rounded, he could certainly see himself challenging Johnson.

Jussier “Formiga” da Silva

Formiga is an interesting possibility, too, should he top Makovsky in their upcoming fight. He has been hyped as a top flyweight since his Tachi Palace Fights days. He was among the first group of flyweights to enter the UFC, and he immediately jumped into a title eliminator match with John Dodson. Formiga was no match for Dodson, though, and came up short in their fight. Since that bout, Formiga has gone 2-1 with his lone loss coming against Joseph Benavidez. Like Makovsky, Formiga faced Jorgensen in his last fight. Unlike Makovsky, he was able to finish the rear-naked choke he caught Jorgensen in.

Formiga is very well rounded. If he can avoid the big shot, he could pose huge problems on the ground for Johnson. His losses have been to top talent like Benavidez, Dodson and Ian McCall, so he is certainly no stranger to marquee fights.

Formiga has a great submission arsenal at his disposal and his grappling is near the top of the division, as shown by his eight submission victories. He’ll have to get past Makovsky, though, which is no easy task.