According to Rick Reeno at BoxingScene.com, Lucas Matthysse has withdrawn from his September 17 fight on the Mayweather vs Ortiz undercard, which was going to see him face Erik Morales for the vacant WBC junior welterweight title. Matthysse has fallen ill and wouldn't have been 100% for the fight.
What this means for the PPV undercard, where this was arguably the best fight on the entire show, is unknown. One option might be Anthony Crolla (21-2, 9 KO), who was set to take an easy fight on the off-TV undercard, and was at one point supposed to be Morales' opponent on the show. Crolla was first bumped by Jorge Barrios, who then had visa issues and was replaced by Matthysse, to the delight of fight fans.
Whether or not Crolla would take a fight against Morales on nine days' notice is another question, and the idea of Crolla replacing Matthysse is just speculation at this point. If Morales is entirely pulled off of the card, Golden Boy may have to bump another fight to the main card. The best option there might be the welterweight ten-rounder between Said Ouali (28-3, 20 KO) and Carson Jones (31-8-2, 21 KO).
This could also open Morales up to a December fight with Amir Khan, which has been talked about plenty, but mostly by Khan and Golden Boy, and not so much by Morales.