Egyptian centre-back Hegazy had already undergone cruciate knee ligament surgery in December 2012, but suffered a relapse in training.
Several different sources suggest the Viola could bring back Kroldrup to make up the numbers.
The veteran Dane is currently out of contract after a season with Pescara and also of interest to Livorno and Spezia.
It would be a return to Fiorentina, where the 34-year-old already played from 2006 to 2012.
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