Olympic gold medal winner Luke Campbell, who recently retired from the sport, has given praise to WBC lightweight champion Devin Haney.

At the same time, Campbell is shaking his head over the ongoing situation where the top fighters at 135-pounds are failing to fight each other.

Campbell was knocked out by top lightweight star Ryan Garcia back in January.

The big four at 135 include Garcia, Haney, Gervonta Davis and Teofimo Lopez - and there doesn't appear to be any movement in terms of them fighting each other.

Davis recently won a WBA "regular" title at the junior welterweight limit of 140, Lopez has a mandatory due to George Kambosos, Garcia could be facing WBC interim-champ Joseph Diaz.

Campbell feels Haney is the only boxer, among the top four, looking to fight everyone.

"It is just frustrating really, they all call each other out but none of them fight each other," Campbell told Mirror Fighting .

"I don't get it, they all have a huge amount of talent why not just fight each other? Fair credit to Haney, he is clearly looking to fight these guys, so he deserves fair credit. But you look at 'Tank' Davis, who has he actually fought? Because all the titles are taken at lightweight and at 140-pounds.

"You have Garcia calling him out all the time it might happen, you have got Haney and Lopez calling each other out and I believe Haney would want the fight and Lopez has said he wants it so why not take it. I took all the fights that were offered to me, anyone who called me out I fought, so I just don't quite get it at the moment."