Milan Lalkovic has been ruled out of action until the new year.
The Slovakian has struggled with injuries in both of his Achilles for the majority of this season.
As a result, the complaint has restricted Lalkovic to just two Pompey appearances since Kenny Jackett was appointed manager.
The winger returned to action in the Blues’ 1-0 win against Charlton in the Checkatrade Trophy earlier this month – but he aggravated his problem at The Valley.
On Twitter, Lalkovic revealed he met a specialist in London to discuss his setback yesterday.
And he later posted a picture wearing a protective boot on his right foot and said: ‘That went well. Another six weeks.’