Donaire barely did much at Featherweight other than a TD win over Simpiwe Vetyeka and a stoppage loss to Nicolas Walters. Considering that Donaire couldn’t handle Walters’ size and power he wouldn’t be able to last long against Lopez. Lopez KO’s Donaire in 3 rounds after a fun shootout.
And it's not like Donaire hit any harder than Sanchez. Sal had more power at 126, and hit Lopez 10,000 times and never took him off his feet in either of their fights. Lil Red had a solid chin. Donaire would be fucked.
I remember seeing a clip of Lil Red Lopez at the HOF - he's a BIG, solidly built guy. A much larger man than Donaire. Looked to me like Lopez probably walks around at a solid, in-shape 160-170. He must have had tremendous discipline to make 126 in the 70s. If Lil Red were around today, he could make 126 more comfortably and come into the ring at 140.
Lopez was never a 'big' featherweight, in terms of weight he was generally well under 126 until later in his career.