It really depends. We know he has been limited in his change-of-direction training/running - but if he has been able to do a lot of straight line running at pace (and potentially some repeat sprints etc) then fitness may not be as big an issue.Yeo wont be playing till the bye.
He has been running a boundary all pre-season and hasn't done anything that intense since he was injured last year.
He will need do a mini pre-season for 7-8 weeks to build up that fitness needed to have a strong second half.
Of course as he gets back into full training he will have to listen to his body and judge any symptoms etc (it is pretty different to what he has done for close to 12 months). But provided he can continue symptom free I doubt he is that far behind fitness wise that he needs 7-8 weeks.