A tweet from his mum, Marie, today confirmed that he is no longer self-isolating, after testing positive for the virus on Tuesday.
And on his first day without being restricted in his movements, the Irishman reported back to training – albeit on his own.
It means the winger will be in contention to face AFC Wimbledon on Tuesday night after sitting out last week’s games against Bristol City (FA Cup), Peterborough (Papa John’s Trophy) and Fleetwood (League One).
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Curtis’ last game came more than four weeks ago when the Blues beat Hull 2-0 on December 18.
He first became unwell prior to the Cup clash with City last Saturday.
In his absence, Michael Jacobs started the games against the Robins and Fleetwood, with Pompey fielding a second-string starting XI for their Trophy game at Posh.
Confirming her son’s return, Marie simply tweeted: ‘Back at it today training on his own.’