If not Canelo Alvarez, who should Gennady Golovkin fight next?

Gennady Golovkin, left, stopped Vanes Martirosyan in Round 2 for his 20th consecutive middleweight title defense. Photo provided by Tom Hogan/Hoganphotos/GGG Promotions

Unified middleweight world champion Gennady Golovkin made it clear following his second-round destruction of late substitute Vanes Martirosyan on Saturday night at the StubHub Center in Carson, California, that he most definitely wants a rematch with Canelo Alvarez in September.

They were, of course, supposed to fight each other this past Saturday night in a mega event in Las Vegas, but the sequel to their dubious draw last September was canceled after Alvarez failed two drug tests.

GGG, however, was still determined to fight, so he took a gargantuan pay cut from around $20 million he'd have made for the rematch to $1 million to fight Martirosyan. Golovkin didn't want to waste a training camp, wanted to be active and wanted to give his fans, especially his Mexican ones, a Cinco De Mayo boxing event. So Martirosyan got the fight and Golovkin blasted him out in the one-sided mismatch everyone expected.

Now comes the difficult task of putting the rematch with Alvarez back together for Sept. 15, the same Mexican Independence Day weekend they fought on last year. Given the massive amounts of money involved -- it's easily the biggest fight for both guys -- it figures to happen even though there will likely be a rocky road to get there.

But what if the deal doesn't get done? It seems unlikely, but GGG and Canelo are both proud, stubborn men so it is conceivable they could screw this up.

If that should actually happen then what will Golovkin (37-0-1, 33 KOs) do for what would be a record-breaking 21st consecutive middleweight title defense if he wins? There are a number of interesting opponents in the deep 160-pound division. They won't bring as much money or attention as a rematch with Alvarez, but in the event the rematch does not take place this fall here is who I'd like to see GGG fight instead, in order of my preference:

1. Jermall Charlo (27-0, 21 KOs)

Of all the quality opponents, I happen to think this will be the most exciting fight as well as one that I have no doubt would be competitive. Charlo, who holds an interim title, is one of Golovkin's mandatory challengers, and though the fight is not yet due, nothing would prevent them from getting cracking on a deal now instead of waiting until it's due. Charlo brings youth, power, skills and a villain attitude he loves to embrace, which would also make for a fun promotion. The former junior middleweight world titlist won that title by knockout and won two of his three defenses by stoppage. Then he vacated to move up to middleweight and has won both of his fights at 160 pounds by knockout, including a very impressive second-round destruction of Hugo Centeno Jr. on April 21. Make no mistake: GGG-Charlo is a serious fight that would be terrific.

2. Billy Joe Saunders (26-0, 12 KOs)

Golovkin owns three of the major titles but his long-stated goal has been to unify all four belts. Saunders holds the only one Golovkin doesn't, so a fight between them would be for the undisputed world title -- as long as GGG isn't stripped by the IBF, whose mandatory defense against Sergey Derevyanchenko is due and the subject of an ongoing fight between camps and the sanctioning body. That aside, Saunders brings good skills to the table and is capable of outboxing anyone for long stretches, so his style might make for an interesting clash with Golovkin's brute power and skills. England's Saunders is also a top-notch trash talker who would also bring some of the passionate British fans to the fight, and whether their guy is winning or losing they sure liven things up.

3. Sergey Derevyanchenko (12-0, 10 KOs)

Derevyanchenko is a mandatory challenger and the fight is due. The IBF gave Golovkin an exception to fight Martirosyan but declined to allow its title to be at stake in the bout. It also ruled that if Golovkin faced Martirosyan, the winner was obligated to face Derevyanchenko no later than Aug. 3. The issue is the subject of a battle of letters to the IBF from each camp's attorneys as GGG's side seeks to avoid the fight now and not be stripped while Derevyanchenko's camp is pressing for the title fight he earned. There's a good chance Golovkin will wind up being stripped if he doesn't fight this mandatory next, but politics aside it's a heck of a matchup. Derevyanchenko may only have 12 pro fights but he was a monster amateur (as was Golovkin) and a 2008 Olympian for Ukraine. He also makes crowd-pleasing bouts and I can see no way this wouldn't be a fun fight between guys with around 600 amateur bouts between them.

4. Daniel Jacobs (34-2, 29 KOs)

In March 2017, then-secondary world titlist Jacobs gave Golovkin by far the toughest fight of his career but lost a closely contested unanimous decision -- 115-112, 115-112 and 114-113 -- in a fight many thought Jacobs won despite getting dropped in the fourth round. It was an excellent fight and Jacobs wanted an immediate rematch. Golovkin said he would consider fighting him again. Since that bout, Jacobs has won two fights against lesser opponents, including a struggle with Maciej Sulecki on April 28 in an elimination bout to position himself as an eventual mandatory challenger for one of Golovkin's belts. A rematch should happen eventually based on how good and close the fight was last year and the fact that Jacobs is the most well-known name on this list thanks to his contract with HBO, which has marketed the heck out him for the past two fights since he signed with the network. But as good as the bout probably would be, it is not at the top of my list because I thought Golovkin definitely won their fight, albeit in a close call, and because I am usually more interested in seeing a new fight before a rematch unless there is a truly compelling need for it.

5. Ryota Murata (14-1, 11 KOs)

Murata won a 2012 Olympic gold medal for Japan and his lone pro loss was a split decision to Hassan N'Dam last May that was so controversial it was essentially a national scandal in Japan, where Murata is one of the most popular athletes. In the immediate rematch, Murata easily defeated N'Dam by seventh-round knockout to claim a secondary world title (that makes him a GGG mandatory), so he should be undefeated. When Murata was preparing to face Emanuele Blandamura, whom he knocked out in the eighth round on April 15, Top Rank's Bob Arum, Murata's co-promoter with Akihiko Honda of Teiken Promotions, said he hoped he could make a deal with Golovkin's camp to bring him to Japan for a fight at the Tokyo Dome (where Buster Douglas upset Mike Tyson) in what would be a mega event in the country. Golovkin likes big events, which is one of the reasons he agreed to face Kell Brook in London in 2016. Tom Loeffler, Golovkin's promoter, and Arum both say they've talked about the prospect of the fight with Murata in Japan, which might not be as competitive as some other matches but it would be a huge event there and a lot of fun.

6. Demetrius Andrade (25-0, 16 KOs)

Andrade, a 2008 U.S. Olympian and two-time junior middleweight world titlist, left that division behind and moved up to middleweight in October and shut out then-undefeated Alantez Fox in a less-than-exciting fight. But while Andrade might not always make the most entertaining fights, he is a very talented boxer with a fun personality who has been calling for a fight with Golovkin for a while. His career has been beset by long layoffs, some that are on him, but when Alvarez's positive drug tests forced him out of the May 5 rematch with GGG, Andrade immediately piped up and said he had been in the gym and would be happy to take the fight on three weeks' notice. The GGG camp never made a call to even inquire about the prospect at a time when they were desperate for an opponent. The reason is simple: Andrade is a tall, rangy, experienced southpaw with supreme amateur credentials and he's a superb boxer who can move and who has underrated power. But he also doesn't have much of a fan base and brings little economic muscle to the table, not to mention his fights don't always entertain, so he's never going to be at the top of anyone's wish list to make a big event.