The Pompey loanee has picked up a groin injury during pre-season at the Gulls.
Bass, 20, returned to his parent club for a scan '“Â which revealed he has a slight tear.
Torquay boss Gary Owens allayed fears the Blues academy product will be out for a significant period of time.Â
But Bass could miss his side's opening league game of the campaign at Chelmsford City on Saturday, August 4.
Owens told devonlive.com: '˜Alex has had a scan back at Portsmouth and it has shown up a little tear.
'˜It's not a bad injuryÂ but he's touch and go for the start of the season.
'˜If he misses the first week, that could mean he misses three games.'