Aaron Pryor coming out of a time machine from 1982. No current 140lb fighter would make it past the 4th round. The scary thing is that Manny could probably make 135 and still be comfortable. He supposedly woke up the day of the Clottey weigh-in at 142, ate a full breakfast and lunch, and then weighed in at 145 3/4. Manny is dominating top welters and he's really a beefy lightweight or small junior welter. A young Mosely at 135-140 vs this version of Manny would have been awesome, too.
At 140lbs, not even Floyd can win against Pac. Floyd will be too weight drained to be competitive the whole 12 rounds. At these current fighters, no one can win against Pac at 140lbs.
pac would be seriously weight drained at 135 by now, the same way he was when he fought marquez at 130 for the second time where he almost didn't make the weight and had to weigh in like a skeleton. but at 140, pac would be borderline lethal. no 140 pound fighter right now would take his power and his speed would be a lot better at 140 cause he would be lighter.
Alexander would bust Pac's ear drums worse than Cotto did, just by yelling for every punch he throws.
No one at 140 has a strong chance at beating Manny. The challenges Manny needs are from guys who are close to his talent and skill level who hold size, weight, power and strenght advantages over him. Smaller guys like Tim and Alexander...unfortuately are in some MAJOR trouble......THey just don't have the experience at this time to be prepared for a guy like Manny....but they'd give spirited efforts for sure.