Really tough call. But if a Jr. Middle like Castillejo could ko Sturm cleanly, I have to say Pirog has a very good chance of stopping him. Pirog late KO, 10,11 or 12th round, in a pretty good fight.
At this point I would pick Sturm by decision, but I'm assuming Sturm still has a full tank of gas. That assumpton may be wrong. In addition, Pirog has sufficient power to put Sturm's lights out even if Felix is 100%, so I would not rule out the possibility of Pirog by KO.
to justify my early answer. sturm has a mint jab and i think he can keep pirog at bay until about round 10. he then just has to weather the late storm. and i think he will survive.
sturm got kod by a 37 year old former junior middle champion...went life and death for 24 rounds with journeyman randy griffin........ think its an accident how how he would never fight his fellow countryman abraham? or anyone else not on his pathetic resume?
Sturm seems to have been focusing on strength for a while and he is stronger than he used to be. Although I think it's the wrong approach - he lost speed and didn't gain much power.pirog wins