Anthony Crolla merely edged his Venezuelan rival on the scales, weighing in at 9st 8lbs 5oz, while Barroso came in at 9st 8lbs.
Heroically, 29-year old Crolla captured world championship glory in November 2015 in his hometown of Manchester - courtesy of a Hatton-esque body shot that left the shrewd, cohesive and respectable WBA titlist Darleys Perez in excruciating agony on the canvas - incapable of conquering the count of ten.
A blazing Manchester crowd witnessed history in the making as the 'Million Dollar' - less than a year from sustaining potential life-threatening head injuries after bravely tackling burglars - fulfilled his desired childhood dream of becoming a boxing champion of the world.
That night: emotions sparked, dreams were turned into reality, and a humble, levelheaded Mancunian overcame the odds when it seemed agonisingly out of reach.
The Venezuelan is priced at 8/11, 10/11 and 4/5 in several UK markets, while the defending champion Crolla must overcome odds of 11/10 and 1/1 to avoid his reign ending prematurely.
In fact, the majority of experts and fans are marginally, and perhaps unwillingly, backing Barroso to end Crolla's lifelong dream in style. And it's far from harsh on the Mancunian. Once stopped by a far from venomous-hitting Derry Mathews, concerns have arose over Crolla's punch resistance after an array of gritty, hard-fought wars over his career.
Barroso is at the core of those concerns; brutally ending three-time world title challenger Kevin Mitchell's career in a five-round demolition job in December 2015. The sharp, merciless lightweight is on a souring nine-fight knockout streak, and possesses a spiteful armory to shoot down Anthony Crolla and his Manchester faithful.
The Venezuelan outboxed Mitchell during the early rounds, then stunningly floored him with a single jab before subsequently ending proceedings with a hurtful, sickening barrage of punches against the ropes.
Mitchell is the biggest name on Barroso's resume, however he holds an impressive knockout over Ira Terry last year - almost rendering him unconscious with a single straight left.
Barroso is an underrated boxer in many ways. His frightening power overshadows how he actually finds those shots in the first place. Handspeed, movement, judgement of range are all key for Barroso to take Crolla's WBA belt. Unsettling the champion or scoring a knockdown(s) could mute the Manchester crowd, and Barroso swinging for the fences, out-hustling Crolla on the inside is a major factor in determining a new champion.
Potentially, Crolla's counter-punching can outbox Barroso on the backfoot; sliding to his left to avoid Barroso's money shot - the straight left. Of course, Barroso will eventually land clean, but it's to extent he does. By the time Crolla is tagged, however also in the process of slipping shots, the sting of Barroso's power could be somewhat diminished.
Kevin Mitchell, albeit was outboxed and stopped by Barroso, found diminutive success with the jab at long range. Crolla has excellent positing, judgement of range and head movement - so therefore he has the correct tools to take Barroso late and truly put his unknown stamina to the test.
Darleys Perez, the widely respected former WBA champion, found difficulty landing clean jabs on Crolla due to successive head movement and shot-slipping. Barroso, who yet does the subtleties exquisitely well, could find himself in the same predicament.
With the right tactics - discipline, calculation - and with a raucous Manchester crowd cheering him on - Anthony Crolla can overcome the biggest and most dangerous fight of his life and cement his place among the lightweight elite.
Prediction: Anthony Crolla def. Ismael Barroso by unanimous decision