Relegation-threatened Livorno have sacked Domenico Di Carlo after just 88 days in charge and re-appointed Davide Nicola.
Virgil van Dijk claims he knows nothing of interest from English clubs and is keen to prove himself in the Champions League with Celtic.
Manager Peter Taylor has moved to bring in Hewitt with current right-back Michael Harriman away on international duty with the Republic of Ireland Under-21 squad.
Highly-regarded Hewitt, 19, signed for Ipswich from Macclesfield in the summer of 2012 but has not yet nailed down a regular first-team place at Portman Road, making 12 appearances.
He will now look to add to his experience at Priestfield, starting with Saturday's League One trip to Sheffield United.