I don't think he would've gone on to do a whole lot, and it's pretty likely that whatever underlying brain issues he had would've come to the table whether he'd fought Jirov or not, he's probably lucky he never fought a bigger puncher on that level. I thought Monte Barrett also could've easily got the nod against him if I remember well enough, either way Mesi was in serious trouble at the end of that fight. For me he wouldn't have even beaten Sam Peter, Toney would just have beat the shit out of him and either Klitschko would've scored a big KO and possibly killed him in hindsight.