All three players had been dealing with nagging injuries, and only Showers' absence — his injury happened on Wednesday, apparently, while Roberson and Moore suffered theirs prior to this week — is a major surprise.
Of the three players, Florida will likely miss Roberson the least, despite him likely being the most talented of the trio: Florida is very deep in the secondary, and Vernon Hargreaves III, who may well get his first start today in place of Roberson, has looked fantastic in early action in 2013.
Moore's injury likely forces some shuffling along the offensive line, perhaps forcing Trenton Brown, listed as Florida's second-stringer behind Moore, to start at right tackle. Brown is massive, but also raw, and his slow foot speed makes him most valuable as a reserve. Florida could also shift Max Garcia, who has played some tackle in his collegiate career, to right tackle.
Showers has been used as a change-of-pack back on sweeps and outside runs so far this season, and his absence probably just means an increased load for Matt Jones, Mack Brown, and, perhaps, Kelvin Taylor.