After their highly contentious first fight, Scotland's Taylor was set to box his great rival once again.

However a torn plantar fascia tendon in his heel just before a rematch could be announced put the much-anticipated second bout on ice.

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Now the WBO has indicated Taylor must make a mandatory defence of his title against American star Teofimo Lopez.

"I have become undisputed, fighting on the road. To say I am afraid [of Catterall] is ridiculous," Taylor told Sky Sports. "I just laugh.

"There was no-one more than me who wanted to put this right. But this will happen."

Taylor did hold all four of the major 140lb titles, but in an effort to ensure the Catterall rematch happened he vacated three of those belts so he wouldn't be diverted by other mandatory challenges.

Then the injury struck. "I did it the Monday of the Chris Eubank-Liam Smith fight [week]. I did it in sparring. I just felt a pop and a tear, and just horrendous pain," he explained.

"I stopped sparring straight away, took the boot off and it was red raw and my heal was swollen and inflamed. I went to see the doctors on the Tuesday and got a scan on the Wednesday. Got the results back on Thursday and it was a really bad injury, a complete tear.

"My foot was immobilised. It was pretty bad. You're at least six to seven weeks off your feet."

The Scotsman had been determined to "put all the doubt that was there to bed", having been awarded victory after a first bout that many thought Catterall edged.

"[I was ready to] move on with my career, and then that happens. It's one of those things that happens and I just have to go with the punches".

"I'm gutted," Taylor said. "We were about to announce the fight at the Liam Smith fight. I was pretty gutted, I gave up a lot and sacrificed a lot to make this fight happen, vacated my titles to make it happen."

However this intervention from the WBO has changed his plans.

Lopez was a unified lightweight champion and moved up to 140lbs after losing the WBO, IBF and WBA belts to George Kambosos. He has won twice in his new division, stopping Pedro Campa and then edging past Sandor Martin on a split decision.

WBO chairman Luis Batista Salas outlined the terms of the fight in an official letter which stated: "In the wake of the recent postponement of the Josh Taylor-Jack Catterall WBO voluntary title defence, the WBO world championship committee is hereby ordering the commencement of negotiations for the mandatory title defence obligation in the junior-welterweight division between Josh Taylor and Teofimo Lopez.

"The camps herein are granted 10 days upon issuance of this notice to reach an agreement or purse bid proceedings shall be conducted pursuant to WBO regulations of world championship contests.

"The minimum bid for the junior-welterweight division is 150,000 US dollars. Any of the parties involved may request a purse bid ceremony at any time during the negotiation process."

"They've ordered me to fight Teofimo Lopez. It's one I want to do, It's the only belt I've got left, the WBO, so I want to keep it," Taylor said.

"If I went and then fought Jack I'd be fighting him with no titles. I want to keep the title. They're all my belts, but I want to keep this one," he said. "I'm going to fight this."

"Further on down the line, Jack and me can still fight. I don't know what's going to happen now. I definitely will [but] it's out of my control, it's not my fault the WBO got in touch," he said.

"At the end of the day it's out of my control. This fight is a much bigger fight than the Catterall fight. It's a much bigger fight and it's a harder fight. He is a much higher calibre of opponent, he has been at a higher level, he's been in with better fighters. He's done the business and got the t-shirt. I think it's a better fight."

The rivalry between Taylor and Catterall remains as fierce as ever. "It's turned up a little bit. He has made it a little bit personal," the WBO champion said.

"The way him and his team are crying about it and moaning like little kids. They're moaning cry-babies, sore losers is what they are.

"I don't think Jack Catterall is going to go anywhere.

"He will get the chance to rectify it, but I highly doubt he is going to get near me."