The 35 year-old’s spirit was questioned in October when Rubio was blasted out in two rounds by Gennady Golokvin, although the three-time world title challenger is adamant that making the weight and a long career without a break was behind his poor performance.
“I was physically tired after my last fight after so many years in boxing. I always knew I would come back because boxing is my life. I’ve been working for 5 months to get back in shape and I am in great shape,” said Rubio.
“It was hard to make 160 for the last two or three fights. I left too much in the sauna to make weight. But now at 168 I feel great. This won’t affect my punching power. It’s something new that I’m looking forward to.
“I’ve had the right sparring partners this camp. I’m in good shape and I definitely have the right strategy for this fight,” he added.
Rubio has been pitched in against another fighter attempting to come back from a loss as Dirrell eyes a victory to erase the memory of losing his WBC title to Badou Jack in April.
Opponent Dirrell, 30, could well earn himself another crack at a world crown if he can overcome Rubio in Texas as part of a double header with the rematch between Jamie McDonnell and Tomoki Kameda at the American Bank Center in Corpus Christi, Texas.